I have an Epi Les paul custom this one and I think it looks a little bit plain, so I have decided that I am going to replace the pickups with the gold EMGs, replace the knobs with gold ones, and the tuners with gold groves... however I don't know anything about bridges...

What bridge would be the best to put on there? I want a gold one..
try the Graph Tech Resomax gold bridge. Its a big upgrade from the stock epiphone bridge
The Gotoh or tonepros import tune-o-matic are drop in replacements and are both available in gold
Epiphone Les Paul Plus Top
Jet City JCA5212RC (SLO Modded)
Ibanez WD7 Wah
Mad Professor Sweet Honey Overdrive
TC Electronic Flashback Triple Delay
TC Electronic Trinity Reverb