I think the SS kit 100% NOT worth it. If your the type thats worried about warrenty then thats your only safe option for tunning, so you might think its worth it. This will increase your insurance group from 14 to 15.

The SS Kit is just spring/shocks + filter + remap + discs/pads + wheels for £3000! All this and better items can be had for fraction of the cost.

The turbo on the 500 is rated at 180bhp and to see this alone will cost you a fair bit of money and you will be lucky to see it...

TMC Box = £300 + Modification to box = ??
Induction Kit = £350
Full Exhaust = £400 - £500
High Flow cat (200 cell) = £600
Uprated Actuator = ??

As for 200bhp i personaly wont go there unless you have a larger turbo fitted, then your talking more money again.

You might see 200bhp with just wacking the boost up but when things fail they are not cheap, for example 4 inch pipe splits in the engine bay above the turbo thats £140...