As far from JBS as possible !
If your looking at the diesel 170 that has a DPF as well mate. All VAG diesel cars from the PD170 56 plate and newer have DPF`s because of the new EEC emmission laws. I hate to swear but JBS/Custom code can do this as well as P-Torque and several other companies. You might want to find out how it effects the car at MOT time as to weather you need to refit the DPF and flash the ECU back to stock to pass as the DPF is wired to the ECU unlike a CAT which can be removed from a diesel car with no MOT issues. The PD 170 engine can handle the power no problems but a free flow backbox would be helpful if you want to get the most power out of the system and unless the torque is kept below 300 lb a new uprated clutch might be need down the line at some stage but to me personally it would be worth it for the grin factor.
06 Audi 2.0 PD140 Sport TDI Quattro S-LINE.
Old engine 330 bhp @ flywheel 263 bhp @ wheel 490 lb torque.
Audidriver write up HERE
Now stripped and playing with an uprated Cryo treated engine fitted with bigger turbo,water/methanol,uprated injectors etc etc.Wanting 400 bhp and 500 lb torque.
Other car 500+ bhp MK4 Golf R32 turbo