Electric and air lockers will bother require setting up the ring & pinion gears, no advantage to either one there. An electric locker requires running wires to the diff. An air locker requires running air lines. 'Bout the same either way there too.
An air locker does require mounting, wiring and plumbing an air compressor (as well as buying it). The wiring probably isn't too much worse than wiring an e-locker, but the rest is definitely more work to do an air locker. 'course the advantage is then you also have on-board air, so you do get something for the extra effort.
I know there are quite a few people that are pretty happy with friction-type limited slips, but personally I wouldn't put any effort or money into one. If it were me I'd put either some type of locker in the rear, or maybe a True Trac gear-type limited slip. Having said that, I'm sure there will be people telling you that rebuilding your current LS is cheaper (and they're probably right) and that it will give you all you need. And they may or may not be right about that. It depends on what you need..