Still deciding how far to go with it as will hopefully only be on for just over a year..
Get the T304E turbo Dave, you know it makes sense, you will get your 300bhp you are after on stock internals, and if you do ever upgrade internals it still has power to take you further 
Ive already got a Garrett sat in my living room

Capable of 300 at the wheels of a 4wd pulsar, so with less loss, might see 320.. LSD and 4wd - less, that should be enough..
Greed, its a powerful thing.