Well if it helps. My Ceramic Nailbomb/ coldsweat combo used to be in my Les Paul before I put them in my Ibanez, and I can tell you a Les Paul is a lot chunkier and heavier sounding than an SG. In my Les Paul they sounded perfectly fine, so you don't need to worry about your guitar not having enough top end. I do know what you mean tho.
Also you was worried that the Cold Sweat wouldn't have enough mid range - If you look, it's the same as the Ceramic Nailbomb.
I personally prefer the Ceramic Nailbomb because I play metal, but it's now in my Ibanez which is used exclusively for Progressive Metal (Dream Theater, Symphony X, etc.) It's a great pickup and plays leads very well, but I think the Alnico Nailbomb would be better suited to Instrumental Styles tbh - and it's also very tight for Alnico.
It actually depends, what kind of instrumentals do you actually play? Emotional, or complex Vai/Petrucci (Late Dream Theater, not early or his solo album) style?