Or do it yourself... I've been modifying my car for over 2 years now... 80% of the work is done by me and I'm not a qualified mechanic. This forums provides amazing DIY tutorials and you can also search on google and YouTube. There is also a copy of the service workshop manual floating around that provides you with detailed steps.
Speak to your tuner about the combination of parts you need, fit them yourself, then get it tuned.