Well, I too have size limitations in my own apartment (about 1050 sqft), so I'm well aware of trying to set up a viable system in limited space.
The room/area comes out to be about 1345 cubic feet, so the good news is, you shouldn't need much subwoofer
The other item I should point out is it might be difficult to setup surround speakers, depending on how much you have between any furniture and the walls. My left surround is actually a good couple feet behind my listening position while the right surround is almost at 90 degrees. Also, since I have towers for surrounds, that speaker sticks out a bit in the walking area. So, long story short, if you have similar issues with placement and space, wall mounting or using just left/center/right speakers might be a better option, even though I love the surround sound.
I think most any receiver around $300-600 will do just fine, provided it has enough connections for you. I'm also a fan of the Audyssey Dynamic EQ and Dynamic Volume so I can get better dialogue clarity and less dynamic range (neighbors wouldn't care for hearing the loud booms
) for TV and movies, but I do have that turned off when listening to music. I'm not too up to speed on the receivers currently out on the market in that price range, so you might want to spend some time searching the forums, but I would look at brands like Denon, Marantz, and Yamaha. Also, if buying refurbished is ok, Accessories4Less has several models that might appeal to you.
Accessories4less: High End Audio at Low End Prices!
^^^A4L also has some speakers from KEF that might be worth looking into.
As for speakers, I think you can do better than Polk Audio. If you have a Fry's by you, you should keep an eye out for when they put
Infinity Primus P363 speakers on sale for $99/each. Even above that price it's a great speaker and at that price, you may as well go to the store with a ski mask and a gun.
I purchased a pair of the previous model (362's) for $149/ea from Fry - probably the best deal I've gotten on audio gear, outside of some subwoofer drivers. But I digress...
There is a couple of center channels that match the P363's. I would try and get the PC351:
Primus PC351 - Infinity
One thing about shopping for center channels is you want to measure the space you have to work with to ensure it won't be too wide, deep or tall for your TV. That was an issue I had before I bought a stand with a mounting system.
For subs, you should measure how much space you have on the floor. If you have any flexibility in being able to have different locations, it can help in getting the best sound. I think your first stop should probably be the HSU Research and consider something like the VTF-2 MK4:
VTF-2 MK4 Subwoofer
Fairly narrow width and should outperform that Mirage easily.
Oh, and if you aren't familiar with them, you should go here for the cables/speaker wire/etc. you will need:
MONOPRICE!!!