You have a key statement in there, all the tools and needed equipment to do the job. The other issue is time and space and knowledge. Which you stated you have. I'm sure if I wanted to do one myself I probably could, after I spend a g spot on tools.
The other issue for me, not sayin everyone can't, but if I screw it up I'm out that 2500 and then some, depending on what else goes with it. There goes the extra turbo lol....
A reputable builder will stand by there wears, if you go into it truthfully and not build a trans for 500hp and turn up the heat to 6-7 or 800 hp then you'll probably be in the same boat.