The mics I most frequently use for electric guitar are the AKG C12-VR, which is perhaps my favorite (which is the same capsule as the 414-TLII), and a Sennheiser MD409, which is easily my favorite dynamic mic. I'll use the 409 on both electric bass and guitar amps. You mentioned the R84, which I found works ok with my Ampeg B15 for bass. There is a miking technique I sometimes use, where you close mic the cabinet and then you use a ribbon mic a few feet off in whatever you determine to be the sweet spot for phasing. The R84 works pretty well in that situation, but I honestly prefer a RCA 77 or 44 in that situation. I think it has something to do with less high end response those mics.
Honestly though, if you want just one mic for the application and you don't want to spend a great deal of money or you don't want to worry about damaging ribbons, I would try the MD409. Don't even bother with the newer 609s. Pieces of shit. But the 409 gives you great low end response and a tight, punchy high end, especially if you like definition in the texture of electric guitar. I wish I had more of them, to tell you the truth.