Re: what would you do differently
i disagree with almost everything said so far, except for upgrading the hardware.
the basics i do with my bikes is:
replace all the hardware with grade 8 allen head socket cap screws
match port the intake manifold and the exhaust (use a dremel or a drill with a grinding bit to enlarge the hole and shape them to match the engine.)
change the plug wire to a 7mm copper core wire and change the plug to an NGK B6HS.
run Opti-2 oil at 100:1 mix right from the start.
ride it hard right out of the gate.
i've never had to re-jet a carb, i don't baby my engines during break-in (and i don't own stock in the company, and all my bikes are still on the road with thousands of hard miles on them.)
heavy duty wheels, sprocket adapters and expansion chambers are all good, but those are upgrades you can do over time. it all depends on how much money you want to put into it. i run 11 or 12 guage wheels and smaller sprockets on my bikes, and i think it's a great idea, but it isn't totally necessary. longevity depends on the quality of the parts you use and how well you maintain them.