Anyone had trouble balancing Weld Draglites/Rodlites?

We are considering changing Dany's Cuda to Weld's to pick up some needed offset on the rear( they are the only 7' wheels I can find with 4.50 offset)
Their website makes a big deal about all their wheels being "Stud centric" and not "hub centric" and that an adapter is needed to balance them by the stud holes and not with a cone in the center hole.

No shop in Greater Cincinnati I have called so far has this adapter, or has any idea what I'm talking about.

So, if you are running Weld's, how did you balance them?
By using the center hole?
If so, did it prove close enough?

Looks like I can buy my own adapter off eBay for like $150, but I hate to do that if the rest of the world just chucks them up on the center hole and calls it close enough.