Re: Essential Epi LP Mods...
When I bought mine; I replaced pots, 3-way, and pickups right away, output jack, plus basically rewired it with better wiring....and it wasn't long afterward that I replaced the tuners with Sperzel locker's. Had to ream out the pegholes and drill a few set-holes for the new tuners, but it wasn't that hard to do and the result was far better than the stocker's.
I haven't done so yet, but replacing the plastic nut with a bone or graphite nut would be a good upgrade. I also haven't replaced any part of the bridge, but I'm sure some higher quality saddles would at least be one thing to improve on the stock guitar.
Once you've got all that money into it, you could have bought a good used Gibson Studio, slapped a nice set of SD pups in it, and be on down the road. Period.
I love my Epi, but for all the work you end up doing on 'em it almost doesn't seem worth it to get one in the first place if all you're going to end up doing is replace parts on it.
The only Epi I would consider buying right now would be like a Sheriton II, or something in that style. But I'm sure that even in those guitars there'd be need for electronic upgrade.