the do lumpy roms which arnt for r34
but there was a japanese daughterboard they were talking about doing for a while , but i dont know if anything ever came of it . they had done the same board in a couple of s14s from memory so worth giving them a call
i never finished my quest for power from my 34 triptronic , i just got the gtr instead .
i tuned factory ecu is theoretically as good as anything else on the market , easily taking you to the limits of your chosen turbo
with a gcg dual ballbearing r34 hiflow you could see 260rwkw maybe 280 with cams . maybe less cause of the drivetrain loss of the auto
your auto might not like it when you get close to 300kw though , budget a couple of grand to strengthen it
have you thought about a manual conversion ? then your ecu options open up substantially