Sorry guys, still have not figured out what is wrong with my attempted FS advert. But, in the meanwhile, let me remind you that Chas Windridge used to manage 4/4 supercharging conversions with, I beleive, Jackson Racings M45 based kit. I think it was pretty much at its limit with the 1.8. This is the larger M62, so for 2.0 litres+.
Anyway, keep an eye out for the ad, which explains more!
cheers, Colin