If you've gone tech art for the exhaust, I'd stick with Tech art for the other mods (Chip etc).
Expensive but quality items.
In terms of remaps etc there are three levels out there.
1) Stock remap DMS, Revo etc - very nice, great bang pr buck in terms of driveabiity, smoothness and how the car feels on the road. One size fits all, low risk - stays within the manufacturers parameters, not easily spotted.
2a) Stage 2 option A - optimizing the remap with your Exhaust/intake - Revo do a stage 2 with a Milteck exhaust, Tech art I think are your only current option here. This is a stock map set up up still with a one size fits all approach, low risk, modest gains, sense of value for money.
2b)Stage 2 - Option B - Custom remap on rolling road eg Vizu. Unique map created to you car measured and tuned on a rolling road. The guys give good advice on where optimum combinations and limits are
3) Custom Chip - GMC/ Tech Art - full Monty with custom chip for your model of car with the manufacturers own settings. Set up to take advantage of any other mods you have.
Any of these break your warranty but so does having a tech art exhaust.
If I had either Car Graphic or Tech art exhaust I'd go for the corresponding chip upgrade (3) they guys put a lot of effort into designing and building an efficient and reliable upgrade that feels likes it a factory fresh car. Its worth the extra money.
For me I ended up on 2 b) as I had done the milteck route and a single mass flywheel - again the custom remap brought the car back to feeling like an put of the factory model, with no sudden drop offs or soft spots in performance. he Vizu guys were very clear about the point to which I'd be limiting the longevity of key components, so we optimized the cars drive ability within that. We could have had more power but I think Alex link shows the risk, also sometimes more even performance through the rev range makes for a faster on road car than top end power.
