I am looking at putting together a 5.1 surround system in Canada.
Wanted: Front bookshelf speakers and center channel
Rear in-ceiling speakers
Denon receiver (either the AVR-X2100 ($750) or the AVR-X2000($500))
Does your budget price include the cost of the AVR or is that on top of what you'll spend for speakers?
If $2500 is your budget for speakers and a sub I would suggest looking at the SVS stuff that you can get from Sonic Boom Audio.
SVS Ultra bookshelf speakers and a center channel and a PB-1000 sub would make a great system. There's plenty of good inexpensive in-ceilings that you could use to work with those speakers.