Maverick
Iv'e done the standard turbo's to hybrids route before the single turbo was a realistic option and TBH, never gained anything worth while over the standard one's. The only thing I got was more lag and a 600 pound bill for getting them fixed again after 6 months. This may well have been due to poor fitting, but then again....
If I had the choice all over again I'd spend my £1500 plus fitting on a small single, (BL61) kit or similar. For the extra you will spend in cash you'll no doubt feel it was money well spent.
If you go for hybrids you still need to keep an eye on the engine temps, boost and fuel to make the most of them so why not spash out on a single instead