Welcome to the LOC. I allways enjoy meeting and hearing about modified cars in other countries.
Why do you need to lower the compression more? Are you planning on running larger turbos? If so, that set up has sequential turbos not full twin right? So maybe just go with a stage 2 single and leave the compression right where it's at. Your now at or slightly over 400 whp easy. ( of course with an intercooler.)
That's funny, I'm dealing with this very issue right now. The tranny will need to opened up and racebuilt. Upgrade the planetaries, heat treat the sunshell, upgrade the valvebody, and sprags, mill out the pockets for room to add some more clutch packs, boost the pressure and add a tranny cooler. All that should hold up to around 600 rwtq. If you just do the valvebody, sprags, clutchpacks, and tranny cooler, then 400-450 rwtq. And change to AMSOIL ATF.
I can make things much easier for you. Just get the new AEM fic. Retails here in US for less than 500 dollars. I use that as a fully programmable piggy back. What makes this so awsome is that it only alters ignition timing, and fuel control. The stock ecu still does everything else. So I have all the factory goodys and controls. In fact, the idle is even still controlled by the stock ecu!!! Everything works as before.
I'm running stock coils and wires, but I think boosting the coil packs would be a great idea to help produce a larger and stronger spark. And if your using the 3330 spark plugs, you'll need to change them every 3000 miles. So you might want to consider going up to the Denso's or NGK BKR7EIX.