well i just pulled my old epi les paul out of the dusty corner of the workshop. It had no parts on it at all so i have used stuff i had lying around - which all happened to be higher spec.
I went for a gotoh bridge and tailpiece like this
http://www.stewmac.com/shop/Bridges,_tailpieces/Electric_guitar,_Tune-o-matic_bridges/Gotoh_Tune-o-matic_Bridge_with_Studs_Bushings.htmlit was a direct swap for the epiphone one but i would recommend measuring yours to be sure. It has more room for intonation adjustment than the epiphone and is a more solid design which means less rattles and a more solid feel.
i also upgraded the nut to a non-plastic one, i hate plastic nuts on guitars. its always a job worth doing properly
Tuners were replaced with grover rotomatics because its what i had spare, but they are a lot better than the epiphone ones and to help tuning stability a lot. These were not a drop in replacement as they require bigger holes. If you want a drop in replacement get some proper klusons or tone-pros variety of them
I also changed all the pots to CTS, the switch to a switchcraft one and the caps to some old buggers i had lying around
i am sure it sounds clearer than i remember but it has been a while since i had the guitar together with epiphone parts and i changed a lot at once so cannot swear one change made the most difference
pickups were also changed to another brand i had here and i did a full fret dress
i suppose i could have gone further and replaced all the hardware with tone-pros stuff but i think this was enough for the value of the guitar. Is it as good as a real les paul? some would say so. i dont think it quite has it acoustically - possibly because of the multipiece body and cheaper construction... but very few people would be able to tell the difference plugged in. it sounds just like a les paul should