Simple Madass : engine swap?

Still searching the right engine, requirement :
- a wellknown brand
-125cc, 135cc or 150cc
- spare part availability for long term use

candidate : honda supra x 125cc, suzuki shogun SP 125cc, Suzuki FU 150cc, Yamaha Jupiter MX 135cc.
Problems found so far, none of them match directly the engine mounting of the madass. May need to make new bracket for the new engine.
Problem with FU, engine block is too big & may hit front fender, but indeed this 6speed 150cc DOHC is my dream engine for madass.
Will try first my supra x, reason, no need to buy another motor bike :)