Putting 500+HP in car,what should I get for parts?

[Frylok]

I'm building a 355ci SBC pushing over 500HP and I'm going to put it in a 67 chevelle (HEAVY car).Any tips or suggestions on parts for the car?What trans would be best for it?( Id like to go with a TH400 but don't know what company to go with)What rear would be safe?.....Car already has a 12 bolt posi in it but with many miles on it but what company should I go to for parts?also has a TH350 with alot of miles.What suspension parts would be best that would really let me hook on the street and strip.