For Epis, either MIK or MIC, the first parts that must be replaced, in my experience as owner of 5 different Epi models well as the experience of Epiforum members are 1) pup switch; 2) volume and tone pots. These parts are available at Audiophile. Get the Switchcraft ones or the AllParts switches. Both are good with the Switchcraft being better. For pots, AllParts are okay. 500k, either linear or audio taper, I believe linear for tone and audio taper for volume.
FWIW