Re: SG bridge pickup question
I think one major factor to help yourself figure out what to pick is, do you want to maybe err on the side of a subtle change, err on the side of extreme change, or err on something that is 'middle of the road' and see where that puts you for reference?
If you like your tone...I'm a big fan of using a true gain boost circuit, and leave it on, all the time/with that guitar.
Sounds too simple...it's widely used by a lot of guys with GREAT tone (as is the tone knob!), IMO, but not often recommended...putting that out there.
Compared to a clean boost circuit, getting a higher output pickup changes tone (and feel, etc.), not just output. Some people want that along with higher output in a new pickup, of course, so...
There are plenty of good options already suggested in terms of higher output pickups. Lots of tonal variations in there...nothing that is higher output will keep that PAF style tone though, of course, for better or worse. Higher output may not require going for a
vastly different pickup than your current pickup.
There are varying degrees of tonal change and output increase available if you go for hotter bridge pickup...
- The
Perpetual Burn might be a good option to consider. Kind of in the 3/4 of the way to Custom/High output land, similar resistance to the Hybrid, but probably has 2 more similarly wound coils than the Hybrid for a different tonality.
- The
Whole Lotta Humbucker is still probably a fair amount higher in output than your current pickups (gibson site says 7.5k for reference), though not as hot as the others mentioned here and before. This might be a solid choise, may be closer to a PAF with a 'boost' than the above, possibly less of a tonal re-voicing than the others above.
- I had a
Custom Custom in a Gibson SG for years--for years it was my #1 guitar and basically my only guitar. It may seem like a mismatch--all mahogany, dark and high output A2 pickup. It is, in a way, but it was one way to get a tone I could stand, at that time, and I put a custom custom in two other guitars over the course of many years (side note..I have a nickel cover Custom Custom that's naturally aged, if you happen to land on that style pickup and look.

I would actually suggest a different pickup when it comes down to my opinion, however!)...
I don't think there are many bad choices...it just depends on what flavor you want, and where on the spectrum of "only higher output" and "extreme tonal change" you think you want.
Hope you land on what YOU are looking for, whatever that turns out to be!