OK, you're a bit far
If looking at in wall speakers, look at Kef.
AV amp wise, look at a decent HDMI (upscaling) swicthing one as it makes it easier for cabling. If you can get a secondhand Sony 5400ES, they have two HDMIs out so you have the flexibility to run separate cables outputting to a screen and projector. They happen to be excellent too.
Sony STR-DA5400ES review from the experts at whathifi.com
I have the baby 2400ES and its effortlessly good. Pioneer and Yamaha are also excellent but not a fan of Onkyo personally.
I'm not a fan of electric projector screens, but a manual one like this;
Panoview DS-9084PMG 84" 16:9 Pull Down Projector Screen: Amazon.co.uk: Electronics
are very good to get you started. Optoma projectors are great and excellent value 2nd hand.
Take a look at Gumtree in your area for local bargains.
I recently bought an Optoma 720p themescene HD projector and screen for £220 collected