You should never use raked yokes to put longer forks on a standard frame. Ever!
Perfectly true, but they're out there and people do, so Colin needs to be aware of it.
They're lovely characterful bikes that require nearly as much fettling as our BSAs
Sportsters are the unit engines, rubber mounted from 2004, in a twin shock frame
The big twins are nowadays semi-unit, like an early A7
There's 3 frame types for the big twins:
A twin shock, the softail (looks like a rigid), and the big glide tourers
Be interested to hear how you get on.