Cayenne Turbo tuner advice

[Chris14]

Test drove a 2 yr old turbo last week, liked it but didn't feel as fast as I had hoped (not much difference to diesel S). Would still prefer a turbo that I could then upgrade, is there a best in class company in the UK that I can talk to? Probably do a remap and new exhaust (is the Porsche sports exhaust worth considering? I'm a 45 yr old father of 3 and not a footballer...)