just picked up a used holley commander 950 efi system. Pretty bad ass. From what i can tell from screen shots in the owneres manual, it seems similar to the ls1 edit programs. Even better is, i wire up on my 4 banger vw same way you would on a sbc, minus 4 injectors 
Also can control 2 stage, and i believe nitrous-- didn’t look into the nitrous yet as im not to worried about setting that up until the motor/car is running.
System also lets you use a wideband o2 to get a/f down right in each cell.
System was pulled off this car-- http://geocities.com/64duece/ second
twin turbo nova II, 8.32 @ 164-- a quick 8 car at Atco. Guy is friends w/ guys im friends w/, if it makes sense-- thats how i found about this system, for sale… Im sure the fuel maps are going to be way off for my car. Especailly since they had to redo 1 motor as it dumped so much fuel, it washed the rings.
oh yeah, i got head studs, main studs, and send out my money order for rods-- then wait forever until the machine shop is not backed up. Then the motor can go in.
Still shooting for begining of race season to be running.