John,
Clutch, i would go for the helix. heard of a few hybrid TDi's slipping clutches with the sachs.
If your wanting a new flywheel too, this will set you back between £800 and £900.
Turbo, your best bet is a Turbo Dynamics Stage 2 Hybrid, of a GT1749va (If im not mistaken).
For a new unit direct from TD its about £1100
Intercooler wise, you can get the seat sport with forge pipework for around £550. Much better than the forge setup.
Alternatively, you could have a custom setup, using a universal cooler, and then pipe it up however you like. This could cost as little as £400.
Then on top of this, you will need mapping. Personally, i would choose RS tuning in Leeds.
Been in a couple of there hybrids, and they are seriously quick.
Think if you buy the turbo through paul, mapping is around £400-500, but dont hold me to that one.
Also, it may pay to decat your exhaust too, if you havnt already.
Tom.