I would pay Dorian or Spill to come with you. How many supercharged zed has an RAC seen?
but by far the best advice on this thread is to get a car and get the kit fitted yourself - there are way too many unknowns here.
Try just this one for size, you turn up and the S/C is clattering away (Vortech's clatter) you will have no idea (and neither would I, neither would BigPhil and neither would TDi) whether it was normal clatter (they vary tremendously) or it was worsening over time due to jackshaft wear on the S/C (this happens). Trust me, you have to live with it to get to know stock noises and changes from stock noises.
You would have no warranty with Vortech if the jackshaft bearings are shot and you could be into big bucks straightaway.
Alternatively, has the oil been changed every 3k miles and more importantly the oil squirter filter to the blower cleaned (with compressed air) at same interval - if that is clogged, it could go bang any time due to oils starvation to the S/C.
More pragmatically,are there spare belts with it - £100 to import (I'm not joking); do you know how to set back to stock if a belt breaks - fair enough you can ask someone for advice here.
It needs a recent dyno plot, not for power but to show that AFR is acceptable and not running lean - Spill had problems with his running lean IIRC
IMO this is a bad idea - sorry
Tech stuff is over my head but sounds like perfect advice especially the last sentence imo