Don't build an S10, they are garbage! The frames are even weaker than the fullsizes and they have TERRIBLE suspension geometry.
I'm not sure why JDs kit is more expensive, but the reason for the higher cost of my race Chevy kit versus my race Toyota kit (I happen to have kits for both 88-98 Chevys and 84-95 2wd Toyotas) is that the installation for the Chevy kits take much more time. The big deal with the OBS Chevys is the coil-bucket. When going to a coil-over set up with these trucks (there is no possible way you can have a decent LT kit running the stock coil bucket, no matter what anyone tells you. I've been building these trucks for 6 years and have tried damn near everything) you must cut out the entire coil-bucket, leaving a gaping hole to be filled in the frame. The coil-buckets alone take me a solid day to plate in, whereas with the Toyotas, I can have the entire kit on in one day. I'm not sure on FSC policy on posting prices, so PM me and we can talk more specifically about the cost differences between the two.
Don't worry about deciding on shock brand just yet. No matter which manufacturer you go with, you want at least a 2.5" reservoir coil-over. My kits run a 10" travel coil-over (the DD kit pulls 16" and the Race Kit pulls 21" with the same length shock).
The reason there are so few companies that make LT for these trucks is the installation. It takes professional level fabrication skills to install the kit, which let's face it, very few do-it-yourselfers possess. There are a couple of other reasons, but I won't go into them here. PM me and I'll fill you in.
As for the rear, the setup will depend on what you want to use the truck for. If you want to race, links are the only way. If you want to play, a set of Deavers with well valved shocks will handle great. A cage would be the first thing I would do (which I tell everyone, yet no one listens).
In summary...keep the 95 and build it! S10s are possibly the worst platform for a desert truck. Take it from a guy who has building trucks for 7 years while earning his degree in mechanical engineering :).