LS Motor
There is lots of info on these motors. The stock LS1 aluminum block is reliable to around 700-750HP before cracks may be reported. I have seen some go farther, but don't know the longevity factor. A lot of guys are using the LQ9 or LQ4 cast iron blocks with good success. My last 2 turbo builds were 370"-4.030"X3.662", LQ9's. They are relatively cheap. The stock cranks have lived well in excess of 1000HP. Both easily made over 1000HP. If you are looking for a reliable driver, 700-800HP might be less expensive and more reliable. Your drivetrain is definately a large expendature to bring up to task.
If you insist on your LS1 aluminum block, debur the ENTIRE BLOCK and get checked. Get the mains pinned, I've used the DM Performance Girdle, Callies 4" Crank and Rods, Diamond COATED Pistons, (any quality manufacturer will do), all ARP STUDS and hardware, LS9 Head Gaskets up to around 750-800HP, after that O-Ring the block and heads w/copper gaskets. Install bigger diameter head studs-for the boost and N20. Not much different than any other block. Lots of great heads that flow phenomenal out there. Depending on CI, 215-235 range. And 1 7/8"-2" primaries on your headers. Pick up GM High Tech Magazine. It's the Bible for the LS guys. Lots of good info, if you are starting out.
Every engine builder has there own preferences. Due diligence will find a good one in your neighborhood. There are enough good packages to attain your goals. Good Luck.