Dude 300rwkw,man your motor wont be able to handle it for to long.
A head gasket is a bare minimum upgrade for some when going into 230-250rwkw territory.Not to mention fuel pump,550cc injectors (are optional pending on duty cycle),power fc or similar,intercooler,full 3'' turbo back exhaust,boost controller.
Good rubber and good suspension will see good use of this power.Brakes are supposed to be okay at this power but i would also consider that if you were going to go to a track with that much power go a brake upgrade.
A high flow is a popular choice of upgrade,hks 2530 is supposed to be a good upgrade for stock internals.
I say if you are serious about this don't venture far away from the high flow horsepower ratings when choosing a turbo.Mix certain combos to get a better flowing motor to complement the turbo i.e.extractors,cams maybee a match ported & polished head etc..
Cams are considered good because they reduce the dynamic commpression in the engine and as an alternative to cams you could use a exhaust cam gear for a better tune.Either will give a better mid range power output but the cams will give more.
3037 turbo and 300 rwkw forget about it.Im not saying it cant be done it can.Just the motor wont last long at all no matter what way you look at it.For this a rebuild is definently recomended.
Ask others what they have done with their turbo combo to go with it.
As for turbo choices There is a rb25 turbo upgrade thread it should give you a better idea of what choices you can make.