i had the SA-1. difference is about $300 betweent he 2..email me if you want to get a price for either one and i'll give you a good deal.
normally, it comes with 8/6 springs for the SA but i got 10/8 cuz i see a lot of track time.
lifetime...i am not sure but they are fully rebuildable and the master distributor of JIC is 35mins away from my house so there is a solution when it actually gets blown (all shocks, no matter how good or expensive they are, blow)