You seem to be well on your way, but I'll chime in with my thoughts
1) Monster Cable products are most definitely NOT worth their insanely high asking prices.
2) I will actually go further than most people here and tell you that aside from being over-priced, they are also not good. Monster Cable seems very fond of making cables with TIGHT connections. All plugs and connections (RCA, HDMI, optical, etc.) are standardized in terms of size. These are all "friction held" connections - ie. there are no clips or screws holding the cable connector on the plug, only the friction between the cable connector and the socket. So it is very important that the cable connector be the correct size to properly interface with the socket. Monster Cable makes their RCA connectors too tight and their HDMI and optical plugs ever-so-slightly too large. They claim this as an advantage, giving you a "more secure" connection. In reality, you just wind up damaging your socket. When you go to pull out the cable, you might just find that your entire RCA socket comes with it!
3) After the inflated prices and the "extra secure" plugs that damage your gear, you can add to that their disgusting business practices. "Offices" outside of the USA that don't actually exist in a physical location so that they can evade taxes. Threatening small businesses with frivolous lawsuits just for having the word "Monster" in their name. Threatening to sue small cable manufacturers for making cables with a color-coded stripe on them which supposedly infringes on Monster Cable's "trade dress" rights. It's all non-sense. It's all disgusting. And even if their products were reasonably priced and of good quality, these practices would be reason enough to avoid Monster Cable products!
4) Enough about Monster Cable. They are not worth any more time
5) Others have already mentioned Monoprice.com and Bluejeanscable.com. You can add Bluejeans' subsidiary company, TartanCable.com to that list.
You mentioned you are in Australia? I'm not sure what shipping costs from monoprice et al. will be like, but even with shipping, I expect their prices will be lower than what you can find in local stores. That said, if you need a cable quickly and can't wait for shipping, you local hardware store is often a good place to look. Home Depot and the like typically carry generic brand (often RCA or Philips) cables for decent prices and they are certainly fine for hooking up your home theater system
6) For speaker cable, you don't have to be concerned with anything other than getting two leads of copper of a decent gauge. The lower the gauge, the thicker the wire (the gauge is just the diameter of each copper lead in fractions of an inch - so 12 gauge is 1/12th of an inch, which is thicker than 16 gauge = 1/16th of an inch, of course
). In a bedroom, 16 gauge will likely be just fine. If some of your runs are upwards of 30 - 40 feet or so (could be the case with your surround speakers), then use some 14 gauge for those.
Speaker cable doesn't have to be fancy at all. Cheap zipcord or lampcord from your hardware store works perfectly fine.
7) Personally, I like to use banana plugs to connect the speaker wire to the receiver/amp. It just makes plugging and unplugging the speaker wire so much easier. For connecting to the speakers themselves though, I tend to prefer just using a bare wire connection. Banana plugs typically end up sticking out a bit awkwardly from the back of speakers. They are also not necessarily a super tight connection and can sometimes come loose or unplugged from the back of a speaker without you knowing it. So I prefer to just unscrew the binding post and use a bare wire connection to the speakers themselves.
8) There's no need to bi-wire or bi-amp your speakers. Bi-wiring (running two sets of speaker wire for each individual speaker) does absolutely nothing at all. And bi-amping (using two amps to power one speaker) obviously increases the total available power to the speaker, but you aren't at all likely to need that in a bedroom - especially with extremely efficient speakers like your Klipsch.
So...there should be a metal "jumper" that runs between the two red binding posts and a second metal "jumper" that runs between the two black binding posts. Leave those in. With the metal "jumpers" in place, it doesn't matter at all which binding posts you use when you connect the speaker wire. Just so long as you connect one red and one black, it's all good
The back of your receiver/amp will also have one red and one black binding post for each speaker output. Just remember to run your speaker wire so that black connects to black and red connects to red. If you happen to reverse them, there's no danger that you'll damage your speakers or anything. The sound will just be "out of phase" is all. Once you think you have everything properly wired, just run a THX DVD (Star Wars, any Pixar Movie, any other movie that says it's THX Certified on the back of the box) and use the THX Optimizer. That goes through some audio tests and gives you instructions on what to listen for to make sure that you have all of your speakers wired properly
9) For recommendations on receivers/amps, right now, I have to give the nod to Denon. Onkyo is likely the value leader in terms of bang for your buck, but you have a very decent sized budget and Denon is delivering really solid performance along with a nicer user interface and the full suit of the newest Audyssey technologies right now. I'd recommend the AVR-2809CI model for your budget and room size. One thing I really like about that particular model is that it steps up to the MultEQ XT version of Audyssey, which takes more measurements, uses more advanced processing and takes better care of your bass response than the regular MultEQ without the BassXT extension to the program.
