software

I would like to mod my epi les paul studio and change the pickups to Duncan '59 with 4-conductor
I was wondering do i need long shaft pots for all volume and tone controls.

And am I right in thinking that i need audio taper pots for volume and linear taper pots for tone.

Epi's vary a lot in the cavity and sometimes short shafts will work and sometimes they will be a little too short in one of the tone locations. To be safe I would suggest going to long shafts or you may have to whittle on the cavity a bit. They are easier to wire up anyhow ...

Tone control taper is a personal choice but I find I prefer the audio taper pots in all positions.

what is the difference tone wise?

I have put a set of '59 in my Epi LP classic, and couldn' recommend it more. They are bright but not too much, good vintage pup for slight overdrive and crunch. When splitted they sparkle and twang.

About the pots, I have an audio taper pots for the volume, it allows to clean up nicely a distortion sound, and linear taper pots for the tone, which to my hear allow good gradation of the brightnesss of the pup.

I'm sorry I couldn't really explain what it does, but I just wanted to share my good experience with this electronic config.

Hope it can help you.