I've built several home motion picture theater projection systems for people, but they are very expensive. Here is what is typically needed:
2 - 35mm projector heads ($10,000 each)
2 - 35mm sound heads with reverse scan LED reader ($5,000 each)
2 - projector pedestals ($2,000each)
2 - upper reel arms ($500 each)
2 - lower reel arms ($500 each)
2 - 1,000 watt xenon lamphouse ($6,000 each)
2 - single phase 1,000 watt xenon power supplies ($3,500 each)
1- Rack mounted Dolby or DTS digital sound system ($20,000 for Dolby or $10,000 for DTS)
1 - perforated matte white screen, 10' h x 24' w ($1,000)
1 - houselight dimmer (Kelmar brand, 2600 watt capacity) $900
As you can see, assembling your own home motion picture theater projector and screening room is very expensive. Of course the people I built these for several years ago were not concerned with money since they are multi-millionaires anyway.