For the price of the imposters, you could get the real thing. Just speaking for myself, the whole cool thing about my bike is the fact that it's sixty-four years old and still going.
If you're trying to build a quick, modern reliable bike, why not an Evo motor? Harley or S&S makes nice motors. Even a retro build looks pretty cool with an Evo without being a phony. Knuckles are getting kind of expensive, but you can get a rebuilt Genuine HD Pan motor with a title for $6500.00 I just don't get the retro ones because after you pay all that dough, you do NOT have a Pan or Knuckle.
Post Script:
I am not slamming anyone who uses this stuff, it just ain't for me.