I'd personally run Coil springs. First off, they're gonna be cheaper than leaf springs (A LOT), 2nd, if you DO end up doing trails/rocks, you have the flex you need, and 3rd...that dana 44 axle I was talking about already has coil mounts on it. You would need to do a lot of fabbing to run leaves.
Oh and 4th like teamexplorer said, steering is soooo much easier with coils.
And I'd be down to help w/ an SAS...I have it pretty much down to a science.