I don't really enjoy doing mechanic work especially without a lift as it's hard on my back. I highly doubt my abilities to be able to rebuild a transmission. What would I tell my local transmission shop I want installed during the rebuild to give it an even greater and longer life, what mods can they install/do?

 

Depends on what you have to spend on it, and the quality of the shop.
Basically - All Plastic washers replaced with roller bearing equivelents, Hardened Sunshell (4L60s have a problem with breaking the Sun reaction shell, either the splines strip or the splined ring just snaps off entirely), 5 Pinion planets, Block off accumulator pistons in both directions by a good bit (not completely, otherwise it will be unpleasently firm and the high line pressures could cause issues down the line) to firm up engagement. Blockoff Torque converter lockup PWM Valve, that and wide bushings throughout the stator and input shaft, all that and a Wide Band would be the top of the line as far as you can go without building a unit for Racing.
But, all of that is, very, expensive typically. running the 2 grand or so range from a good shop that knows what they're doing. Its why i went straight to doing the work yourself as with most things labour costs go out the window when doing it yourself.

Depending on how you drive and what you do with your truck, Hardened Sunshell, Dual Cage (Metal, there is a variant with a plastic second cage and plastic inside a transmission is already a horrible idea except in certain places), TC PWM Lockup mod and the accumulator blockoff, Wide band, and Wide Bushings, will give you a solid unit for relatively little in actual modifications done that isnt already standard practice. 5 Pinion planets are nice for performance reasons and they are a touch more durable but not an outright requirement, if you had a 4L70 as a core to use they have them stock and they drop right in if i remember right.

Anyone that actually knows what they are talking about please chime in an tell me everything i forgot or described incorrectly, its 3AM so im not all here.

 

If you will be not doing much off-roading or towing, then a standard rebuild should be just fine. A well maintained transmission that is not abused should be able to last another 20 years. Recall that I said "well-maintained" and "not abused."

For me, when I had mine rebuilt they put in a shift kit and a torque converter that was more appropriate for my use of my Blazer for towing. It cost about $2700. They also installed an extra transmission cooler.

But there is a lot of other things you can do to upgrade these transmissions. A lot of these would be more appropriate for when an engine swap is done to a more powerful engine. So if that is in your future or if you expect to use your truck in more extreme ways, then now is the time to upgrade the parts. Some of these (as mentioned above) would include replacing the sun-shell with a stronger unit and replacing the 4-gear planetary gear with a 5-gear version.

Note that all upgrades might not be appropriate for how you intend to use your truck. Decide on what you want to be able to do with it, and then find the upgrades appropriate for that "mission".