Coilovers with triple bypass will give you a very nice ride, so I would definitely second that one. As for the rear, it really depends on your budget. I have seen trucks do perfectly fine with axle over leafs, just make sure you use some decent shocks on the rear too or else you are going to pogo when you catch some good air, or even if you hit some minor whoops at high speed. If you have the money I would always recommend linking your rear end and then running coilovers on the rear as well...but at this point we are getting close to a fully built race truck. A four link set up is awesome because you get all the travel for jumping or just hauling ass, but you also get full articulation for crawling. Either way you go I would definitely gusset the rear axle, Ballistic Fabrication makes a full gusset kit for toyota axles, its decent priced too. Also if you want to keep it leafs but you want some more travel, check out Deaver Springs, they make super arched packs that you can get about 16 inches of travel out of.

 

How hard would it be to put coil-overs for the rear? That's what I want to do but I have had trouble trying to find anything on that for the 1st gens.

 

Its quite a bit of fabrication. You have to link the rear axle, be it a three link or four link set up. You also have a couple of options to mount the coilovers, either straight to the axle, or on trailing arms (trailing arms are the lower links that are built to mount coilovers and a second shock, not just a straight tube). In addition, you also need to build a shock tower in the bed to hold the coilovers on the top end. A lot of the parts you can buy pre-built, such as trailing arms, link mounts and even shock towers, you just have to piece it all together. The cost does add up very quickly though.