1) HTIB heavily frowned upon here
2) Going and auditioning before you buy, preferably with CDs/DVDs you actually plan to use with the system is highly highly highly recommended
3) Generally speaking, if you are serious about getting into home audio the recommendations are that you start with a budget AVR and as good front left and right speakers as you can afford and build up from there.
4) Choice number 1 isn't bad as long as you like how the polks sound. There are many around here who don't like polk because they measure badly, but there are just as many people out in the world who like how they sound, whether from ignorance or because they just enjoy them is for others to debate.
5) Value for money can be had, but how serious you are about getting into home audio will dictate how the recommendations eventually come
I would take a read through this thread.
http://forums.audioholics.com/forums/beginners-audiophytes/79364-speaker-recommendations.html
There are some good speaker advice in here and AVR advice more or less depends on what you want out of the AVR (connectivity, inputs, outputs, calibration software, etc)
Hope that helps a little. For the record, on your budget, what most would consider a "quality" setup is going to bump the budget up a bit (if you want to get a full 5.1 or 7.1 without building up) Quality speakers, AVR, etc cost money and we won't recommend something in your price range just for the heck of it, if there is something better out there for a little bit more. Getting your expectations for this system clear and concise will help you and us.