The finish has to be really, really thick to have any chance of affecting the tone. Even then it's pretty debateable - but some swear that theirs has improved after stripping a quarter inch of poly.
SG Standards, Fadeds, and Specials (the two P90 ones?), are some of the guitars I consider pretty good value from Gibson. I'd choose the SG Classic Faded. An attractive, P90 SG with the late '60s body/neck-join if I was looking to own a Gibson at a reasonable price and went for an SG (although I think the Flying V faded is Gibson's best value guitar bar none).
http://www2.gibson.com/Products/Electric-Guitars/SG/Gibson-USA/SG-Classic-Faded.aspx
If finish is an issue, that's in the Faded's favour, since the finish on them is very thin. Otherwise they're pretty similar. Both Standards and Specials/Fadeds now have three piece bodies. I don't know about the latest batch of Epi SGs, but the older ones I've played have really felt like beginner's guitars.
Oh. This is also interesting - an Epi with the early '60s body shape (deep bevels in the cutaways). Never seen that before. Pretty cool. And a wrap tail too. One of these babies with a set of tonerider P90s (which are top notch pickups) would be pretty good...
http://www2.gibson.com/Products/Electric-Guitars/SG/Epiphone/Ltd-Ed-50th-Anniversary-1961-SG-Special.aspx