Regardless of your opinion of tony, VTT doesn't machine or assemble the motor, and Rebello, who does, has an amazing reputation in the motorsports industry.
I know man, let clarify: I would never give a penny to VTT because of Tony. The is well known and I don't hide it. Rebello is going to build it, VTT is going to make margin/profit off of Rebello's expertise and labor. Other than VTT shop cars, is anyone running a Rebello engine? If so, for more than a year and how many miles? Are they racing it competitively aka Motiv?
Motiv & ABR have a much longer history and proven track(literally) record(4+ years right?) of building N54 engines. I'm not saying Rebello will not build a good engine. I'm saying unless they are offering something different or the price is fantastic, I would go with a known proven provider of built N54 engines, which I believe that only leaves Motiv and ABR.
Once there are more Rebello n54s on the road and track with a proven 'track record' sure go with them if you are comfortable giving your money to VTT. I would say the same of MMP, once it is a proven product(multiple engines out in the wild, many miles, multiple years, real track experience, etc.) and not only being used by the shop offering it, it might be worth a shot.
I see no reason to not go with a well proven solution given the extreme cost of fully building the n54 block and head.
All that being said, to each their own. It's your money, gamble and spend how you want to
