need some suggestions on comporession ratio for my pistons..

ok so im getting just over $1,100 for tax returns....so im going to buy my pistons and rods and get the block machine work done and what ever i have left over will go to my trans that is sitting at the shop...
but i have some questions and hopefully some one could help me out here..im thinking of going with wiseco 11.8:1 - 12.4:1 with a bore size of 81.5
is this safe to run with a rebuilt stock LS head?? or should i do a step down and get 11.1:1 - 11.6:1 with a bore size of 81.5???
and how do i go about tuning the car?? i have a stock obd1 P75 ecu...do i need to buy a chip or can it be tuned as is??
any insight or criticism is welcome..it is my first performance build and want it done right..any help is welcome...thanks in advance
but i have some questions and hopefully some one could help me out here..im thinking of going with wiseco 11.8:1 - 12.4:1 with a bore size of 81.5
is this safe to run with a rebuilt stock LS head?? or should i do a step down and get 11.1:1 - 11.6:1 with a bore size of 81.5???
and how do i go about tuning the car?? i have a stock obd1 P75 ecu...do i need to buy a chip or can it be tuned as is??
any insight or criticism is welcome..it is my first performance build and want it done right..any help is welcome...thanks in advance