I would look for a good local luthier or repairman with a ton of references, preferably related to Fretwork and such. Musicman does re-frets, but only back to the original specs, so if your guitar has nickel frets that's what they'll bring it back to. They are indeed lovely, they feel smooth and like glass when you're playing. Also corrosion is so much easier to handle with them, the frets don't look hazy and unpolished literally ever.
As far as sizes go, the Standards and BFRs always felt like Medium Jumbo Frets to me. I'm sure it's no problem to get any size you prefer installed, it'll just need a proper set up and possibly a bit of work on the nut if you go with larger frets.