This has turned into an interesting thread and a good read, for me the hpfp on the KO3 just isn't worth it for what you get from your car at the end of it and maxing out your hardware (turbo, clutch) is not something you want to do on any car really.
It's easy to get excited about about what other members have done to their cars and what bhp and torque figures they achieved after mapping, but a good question to ask yourself is... If this site was strictly for ko3 cars how much talk about hpfp's would there be and therefore how influenced would I be to buy one? I would personally advise anyone wanting a lot more power to get a ko4 car in the first place instead of killing your ko3, for someone who already has a hpfp ready to go on and is thinking of uprating the clutch a turbo conversion is the obvious next step, PSi Tuning do the upgrade for around £1500 with all the mapping thrown in, I think that's a great price considering what you can pay for a map alone (300 - 600 quid!)