Just know, that's there's so much to know! In terms of "performance" aspect of the theater - in regards to construction, room acoustics, sound-isolation, noise control HVAC system design (noise and ventilation factors) system power distribution, layout, speaker/seating placements within the space, style of seating, equipment selection, cabling, equipment isolation (can degrade system performance if not done right), just to name a few! Just know, that if you're doing everything yourself in terms of the selection and design process, that you're going to be compounding shorfalls likely! Many of us have been in and around, as well as doing this stuff for decades - AND WE'RE STILL LEARNING SOMETHING NEW ALL THE TIME!!! Therefore, just don't expect to "hit it out of the part" on all the issues and choices you'll make, going the DIY route! That's the way it is.
However, if the joy of going that route is the ultimate pleasure project for you, that's another story. Just know that you won't know how it ALL fits together like a professional with a proven track record, if you forgo getting professional assistance.
Seen it hundreds of times over the years. These are constants really.
Infact, I would EVERY TIME recommend to someone who had a reasonable budget- and was going to DIY as a novice/enthusiest - that they even consider downgrading their equipment selection potential choice, and spend the rest of professional help! The end result will most always yield you far better results than if you spend the money on the gear, and don't get some consulting and help. FYI
Choices...
