Really enjoyed my stg1 maxxed it out at around 220bhp, went k03s and stg2 and wasnt and still not impressed by it, im not convinced along with other members that stg2 isnt upto the job for a k03s, nice and cheap to upgrade but if you want the most out of it id say a CC or jabba custom map going on results ive seen.
If your not planning on staying standard id personlly stay standard and save for what you really want, if had to start again this is the way id go, that way your taking one big leap rather than aload of little steps if that makes sense? And would also proberly work out cheaper