Decat will see the most gain, mufflerectomy makes nice sounds and egr delete well that's the first mod anyone should do.

After that the turbo is the limiting factor as the housing can only flow so much air, the mods above just relieve the strain a little.

Anyone's welcome to drop me a msg via pm, since your in Scotland it'd be a case of send me your ecu and I send it back mapped or you buy the flashing tools and vagcom and distance tune it via emails.