I won't get into specifics, but I thought you'd want to know I have almost the exact same setup as you're proposing, so here's some tips to make sure you're headed in the right direction.
1) You're definitely looking @720p in that price range (I have an Optoma HD65)
2) If you mount the screen to the ceiling (I have a Da-Lite High motorized screen--but that may blow your budget), you should be able to put your center channel speaker(s) BELOW it. This will save big $$ on the screen and still sound great (even for TV watching)
3) Get a "high contrast/grey" screen if you get DLP (enhances black levels)
3) The screen drops down to cover my 32" HDTV CRT (for movies)
4) Get blackout shades/blinds for the windows (you'll need it no matter how bright your projector is).
I've attached a couple of pics to give you an idea of how my HDTV/screen/speakers setup looks. Good luck.
Yamaha RX-A2050 AVR (5.0.2)
(4) Polk Monitor 10B's (R/L F/R), (2) Polk Monitor 4's (TM), Polk CS300 center channel
Analog: B&O TX2 Turntable, Nakamichi Cassette Deck 1
Digital: Pioneer CLD-99 Elite LD, Panasonic DMP-UB900 UHD Blu-Ray
LG 65EF9500 4K OLED