i'm pretty much in the same boast as you ...
s2, gts-t, with turbo back 3", hks pod, hks boost control ..
my mod list is as follows, for reasons i'll explain
1. power fc - not installed yet, on the way from japan
2. fmic - about to order
2. fuel pump - ordered
3. regulator - researching
4. afm (z32) - waiting till i find a decent priced one
5. turbo or injectors (high flow) - (sigh) expensive
6. injectors or turbo (high flow) - as above
the reaon i am doing it in this order is that i want all the support systems of the engine to be fully up to spec before i go winding up the boost to 'crazy ass levels'
with a 'phat, fully sick man' turbo ... the last thing i want is a melted piston due to the fuel pump maxing / dying or other such sillyness ...
just my 2 pence worth
(i'm a pom, so am still allowed to spend my opinion in £)