You can't "destroke" the engine with pistons and rods. You must have an EJ20 crank in there.
A 35R is going to be too much for that high CR, low displacement, and pump fuel. You'll fight det the whole way. If you use E85 or race fuel, then you might be able to hold onto it and make that turbo rip. If it's a street car, I'd look into the GTX3076.
Hopefully those pins keep the stock sleeves from bursting. I have my doubts, however. Stock sleeves almost invariably fail with 100mm pistons, and the engines become VERY det sensitive with that little sleeve remaining. The closest you can get to a closed deck block in a Subaru, is the OEM closed deck block from the 91-94 Legacy Turbo (EJ22T).
And this all begs the question - What are you doing for transmission? That much power will vaporize the stock 5MT if you drive it like it should be. If you go for 600+, even a stock 6MT will be ill suited for the power (not to mention short-legged in the ratio department). What's your plan?