Thanks guys for the comments
Having had a good look around at aftermarket parts, and a closer look at the motors, I've decided on getting the LS2. Almost went for the LS3, so close to saying yes to that one, but I just couldn't justify the extra $3000 - that money would go a long way in aftermarket mods!
The LS2 will be compression tested and if thats all good then it will be going in my car. Being as it was recovered from a chop shop not a crashed joy ride, I know it hasn't been sujected to stresses from a crash, and because they obviously planned to onsell it I'm hoping it hasn't been thrashed too much. But any wrecked car is a gamble, who knows what kind of person had it first, and how they drove it?
The L98 that I mentioned before turned out to have a broken accessory mount on the block, I believe it was a power steering mount. So that motor was pretty much junk.