I bought my mounts on Ebay.de for around $170 I believe, they're the same exact one as the 300mm.de mounts and worked perfect.
e32 and e34 manifolds will not fit. Period. I have about 6 hours into mine modifying them to fit. Pretty much the only part that can be saved is the flanges, and I had to modify 2 of those as well.
The V8 booster setup is a pain in the ass to get to fit, it clutters up the engine bay and your brakes will still be hard once you finish since the MC is so much bigger. I'm currently in the design phase of making a different option along the same lines as the Massive booster delete kit, but moved to the left about 4"
Word to the wise: modify the coolant pipe on the back of the motor before you install it! I spent a good weekend of work trying to block off 2 of the holes and making lines to mate the other two to the heater core.
As for a supercharger, it is possible to fit without engine bay modification but you would need to make your own bracket. Not sure if any kits would fit directly.

There may be delays in the supercharger updates though, as I found a bigger engine that I want to swap in first :)
I'll try to answer any other questions too.
Leave a comment: