166 2.OTS How to increase performance?

Hi,

Im researching how to get the best performance from a 2.0ts in a 166, 2003:confused. There are induction kits, ECU remapping, Novitec exaugst systems, using high octaine fuel, But I cant put it all together in a long term package with a garantee that I wont mess the engine and end up bust with a broken engine. Originally I wanted a 3.0 V6 but since I do so much city driving during the working week, its a luxury I cant afford.
I noticed that the original 1998 model had 155bhp, and then some EU regulation messed things for alfa. Would be very greatfull for info from anyone who succeeded in getting a true performance increase with low risk and not spending a great sum of money. Thanks John ps. let me know the downers as well as the advantages.. Apreciated folks..

remap and cda induction package from somewhere like angel tuning will add about 20bhp - i did it to my 2.0 and it makes a massive improvement.

Thanks mate.
Just wondering, if you remap do you have to use high octane fuel every fill up? How does the difference show with the combination. My 166 does 0-62 in 9.5 because its a heavy car. What difference will it make? Any negatives?
Cheers. John

OH. I noticed you have a full sports exhaust? whats the manufacturer?