buy a Ti. will be your best choice: 19s, Brembos, upgraded interior, etc.
IMO, don't try and turn the 2.2 JTS into the performance machine that it's not. if you want more power, buy the 3.2L, rather than spend oodles of $$ on upgrades that don't really yield big gains.
nothing wrong with the 2.2L of course. just accept its power for what it is. it remains a great drive from all reports. subtle enhancements like a new exhaust can make it even more enjoyable, but won't bring significant power gains. spending AUS$3~4K on exhaust, chip, induction still won't make it as quick as the 3.2L.
i'd love a Ti SW. maybe soon.
for an exhaust, probably Lambro/Hi-Tech Mufflers. they do top work. there's also a friendly local member who can supply Ragazzon and Supersprint. for more ideas, perhaps join us (aus alfisti) at ausalfa.com .