Ultimately it depends on what you want from the driving experience. If you want a pin-sharp throttle then the SC is your choice, if you want the big thump in the back then go turbo.
Rear mount turbo kits introduce a considerable amount of extra air to the charge pipe that needs to be compressed before you'll make any boost, so these will add a good deal of lag to the system. I'd happily drive a turbo car, but I'd never consider a rear mount one for this reason alone. In my experience, even removing a foot of charge pipeworks makes a big difference, so you can imagine what adding a couple of meters will do.
Personally in your shoes I wouldn't spunk £10K on a turbo setup, I'd be chopping in for a Mustang instead.