These are what my Local GAS Station put in my Epi Sheri II, and had put in my (ex) Ibanez ARC300 (sorry bout that, strummy...). It's their #1 choice for 'buckers. The link is to Musicians FIEND only for convenience.
DiMarzio 500K Custom Taper Pots
I paid $5 each for them.

I dunno if they match precisely or are actually 500K, and I don't really care. I just know they work really well and do what I want them to do...unlike the stock pots that came on the Epi or Ibanez.