I am a plumber, so my advice is coming from my experience. By the way I would love to see pics of your garage. Since I am a plumber I probably can't afford a garage like your, so please post the pics so I can dream.
I think the Accumulator did a great job

at suming up what you should put in.
A must is the trench drain. Well worth the money, because you will never stand in a puddle of water if it is done properly. Make sure the plumber get the drain plenty low so the concrete gets pitched to it. Concrete guys don't like to pitch slabs--that means they have to do more work to make it look good.
Towards the RO or DI system contact an outfit like U.S. Filter. They specialize in equipement like that. They can give you the best advice and maintain the equipment. Also don't run RO or DI water through a pressure washer. It CAN eat up the pump. Depending on the grade of the water, some of it can get really aggressive.
I would put in the Mop basin and the sink. I hate lifting buckets to a sink to dump them. Or once they are full lifting them out. Thus the mop basin. Then again I hate bending over to clean something in a mop basin thus the sink. If they are both located next to each other it shouldn't cost that much extra.
You might want to consider one of those instanenous water heaters for your garage. It might be a good application for one. BTW I mean one of the gas fired whole house instaneous water heaters.
If you need hose bibbs, I put up links to those in previous post. If you need them, let me know.
Good Luck and please post some pics.