I am buying a new house and finally decided which rooms I would need
the speakerss in. I want 8 stereo speakers (not 8 pairs) in total...4
in-wall and 4 in-ceiling. I just now have to buy Speakers, Receiver and
volume control.

First thing first..how to pick good speakers and receiver?

My budget is $800 for all the speakers. Any recommendation??? Please
advise.

Also where should I buy it from????

I went to the local stores and seems like they seem to be expensive
there. Heard, one do a lot better on eBay. Is it correct? Are there any
other online stores where it's cheap and at the same time, reliable?

What receiver should I go with? I want to have one speaker that
connects all the 8 speakers.

Please help me..