I'd guess that the SG would be the more universally-accepted choice, but I'm mostly basing that on the fact that I don't like LPs all that much, because it's all about me. As for what to look for, there's no advice. Sure, I could say to sight down the fretboard, and check the action, and neck shape, and fret condition, but a layman just doesn't know what to look for. She needs either a salesperson she really, really trusts, or an experienced guitarist who actually knows what they're looking for. That said, it seems to me that the worst-case scenario in this case is a guitar of passable quality. I don't think Epi puts out epically bad instruments, do they?