Get a decent remap mate, you just need a generic one for a diesel with no other mods, you can get one for under 250 quid these days at loads of places. I think Awesome GTI is near you and they do them. The engine is very strong and can handle being permanently remapped. I'm guessing yours is the 130, I have the same engine in my Bora, remapped to 170bhp and 290lbft, it's a fairly mild map that won't ruin my turbo or my clutch. I had it done at 106k and am now on 127k with no turbo or engine trouble. I had to have a new clutch recently but both me and the mechanic think that was just mileage and not the remap, as the DMF was actually still in good condition and didnt really need changing,and it's the DMF that suffers with a too aggressive map - the clutch is rated to 300lb ft.
If you feel like going to Hemel I got mine done there for 130 quid.