Looking for a cheap HT setup

Hello!

I am looking for a cheap (under $500CAN) HTIB setup to accommodate my recent HDTV purchase.

I have a xbox 360 and ps3 that are hooked up via HDMI, that I would like to pass through the receiver.
I also want them to be hdmi 1.3a compatible.

I have looked at the Onkyo HT-S5100 and it seems like it would satisfy my needs. Are there any reasons not to go for it?

Other than that I'm not too picky, other than being as cheap as possible!

How about the Sony HTSS360 ?

Hm I do have another question now.

I have some old Sony SS-C57 speakers (250W) that I could maybe use.
They just have the barebone wires (red/black) so could I buy a plug for modern receivers?

And, would I say be able to buy a receiver+sub+front speakers and use these bad boys as back speakers?