For a pipe, you are definitely better of buying a nice puch pipe and having it cut and welded to fit your ped.
In terms of carbs, most prefer dellorto SHA 16.16 for simplicity for like a 19 PHBG for max performance. Although tuning it will be a little bit harder if you don't have any experience.
Just make sure your bike as stock is ready to handle the extra power (bearings and crankcase is all good).