To get more responses to the pickup question you should really post it in the pickups section of the forums.
I have an SG with Bare Knuckles in it as do a few others here, so I will give you both the opinion of my own personal guitar and pickup choice and the information I gleaned from others. SGs are a thin bodied all mahogany guitar and this makes them a little finicky.
You have a Gibson not an Epiphone so I am guessing that it is all mahogany. You can check this by taking the pickguard and pickups off and looking at the wood. I've heard that Epiphones are laminated so they might have different tonal characteristics. The following comments apply to mahogany SGs.
1. The Painkiller is not recommended for the SG at all. If you want something similar - e.g. for djent, or something quite dry and precise for mathcore etc - then the Aftermath is recommended.
2. Warpigs apparently work quite well in SGs. Use these for big, bassy sounds, tuned down. Grindcore, Sabbath, etc
3. A lot of 'stoner' guitarists use Riff Raffs, which aren't too different from the standard pickups.
4. The Cold Sweat set works very well in SGs. I have the CS neck pickup. A very big improvement on the 490R, that warm mud is a distant memory now. The CS/AM combo is apparently popular and might be the one for you.
5. The Miracle Man and the SG sound like a match made in heaven. As the name suggests this gives you an Ozzy type sound, but apparently it is also very good at metal applications that would otherwise use an EMG 81/85 set (but with more character).
6. Both Nailbombs can work well in the SG, at least in the bridge position. I have heard videos of the ceramic version on youtube and that sounded very good, with less mids than the alnico version. I have the alnico version, which I really like, but it has a very aggressive punky character. It might be a good match for you though, depending on what you are looking for.
7. Apparently the Rebel Yell set also works well, and is a good alternative in applications that might otherwise use the Cold Sweat set.
There is some general advice around on mahogany guitars here but it is worth remembering that the SG has quite distinct tonal characteristics arising as much from construction and design as the wood, so go by the advice of people who have actually fitted pickups to their SGs, rather than statements about 'mahogany guitars' etc. An Explorer or Flying V is a very different beast to an SG.
Mark Lennard from Truth Corroded is an old friend from the Adelaide scene and I can tell you that he has an SG tuned down to B with no problems. I'm not sure what pickups he has, but in his own words "you gotta rock 56 or 60 to 12 gauges to keep the strings tight"
