i think with money, either one works. there's always gonna be someone with a ridiculous build and there's always gonna be someone with a build at any stage blowing it up and adding to the stats.
just remember, even with a 1000hp SR or KA, there will be some guy with a 1500 supra or turboed bike or something faster. always. and IMO, i dont see anyone on this forum that has a car that requires more than 550hp, much less 450 honestly.