Look into a brand new EJ257 casing for the craic!
If you are putting the best of everything into her, it's a shame to use an old block!
On an other (much cheaper) note, just buy yourself a ready assembled brand new EJ257 short block, she will be absolutely happy to run upto and around 400/400
I had an EJ255 (WRX 2.5) running 386bhp and 408lb/ft simply with a TDo5 20g and 740cc injectors and newage WRX top mount for 18 months with loads of trackdays, drag racing and Scooby Shoot out handling course,
After 18 months, just the standard head gaskets finally gave way!
I should have just upgraded to steel gaskets and just put her back together, but I went down the big build route! I hugely regret it! I should have just left it as it was!
So my whole hearted recommendation to you, is buy yourself a standard EJ257 (stronger than my EJ255 was) and fit your heads with steel headgaskets, ARP headstuds and bolt on a TD05 20g/TD06 20g or similar! KENC has one for sale at the moment going cheap! 740cc injectors, induction and a newage STI top mount!
You will never want more from your Type RA
Dan