If you opt for the demon carb do two things right off the bat.
1) Check for metal debri inside the carb.
2) Double check that the jets installed are correct, you can double check this by going to the BG website and comparing what you find.
The carbs are matched to your camshaft, not saying anything against your buddy but I'd speak directly with the BG tech to determine which model is ideal.
Sounds like a lot of trouble but from what I gather, its worth it. Good luck
P.S. While holding your summit card, make several strategic cuts with a pair of scissors, now take the pieces and lay them in the trash.

Save up and pay cash, credit will end up bitting you in the a$$. Kidding,
kinda . Have fun