hmm ive often thought about supercharging ill share my thoughts:
a small supercharger could run off the A/C compressor pulley a small supercharger like the EATON E62 the same one as a mini cooper S this would provide a small amount of boost enough for a noticible difference i reckon without destroying the engine!
the 3.2 is a much stronger engine than my 3.0 so you could get more boost through it unlike myn! my only stumbling point is that the inlet manifold would have to be changed to incorporate an intercooler and the s/c etc
my 2nd concern is that all this extra air going in has to get out and ive already seen that the omega has restricted exhaust manifolds so a set of custom one off manifolds would need to be engineered! which is where i reckon there would be big costs!
still i reckon it could be all done for less than £1500! not bad really considering you could have it all set up for tourqe or bhp personally id have myn set up for extra tourqe as my mv6 i reckon is powerful enough