answer to your first question is
no u dont need to change anything just take out the engine and put the new 1 in.
and for bang for bucks turbo. on stock internals like most people say 6-7 psi if u want more power u can take it up to 10psi but you'll be in the danger zone with stock internals
and yes 10K is more than enuff to get u running into 13's easy your more likely looking into 12's with slicks and so forth liike others mentioned