software

Its gonna match an aph-1n in my les paul classic.

I have a jb in another guitar, but i would want something slightly less output and a bit less of the high mid spike.

I'm heading toward the demon with 300k gibson pots?

What do you think?

The C5 and JB are both outstanding pups. I just swapped out a JB for a C5 in my Genny. They both have A5 magnets, and the JB is wound a bit hotter, but oddly enough, the C5 seems to me to hold its own against the QP's better. It almost seems to have more quot;punchquot; to the JB's quot;airyquot; and open sound.

This is in a basswood bodied, maple/rosewood neck, Tele-ish guitar. YMMV.

(Haven't tried a Demon.)

I had an ESP (with an alder body) with a screamin' demon and I didn't like it : too much top end! I put in a JB and it's a lot better.

Custom 5 or Custom Custom. You'll like either one.
C-5 is tighter, punchier, and better for cleans.
CC has more warmth in it's lower mids and the treble is rounded off, making it silkier and creamier sounding.

what are they like split?

Honestly, I rarely split my bridge pickups, although I split the necks quite often.
Since most of these pickups are over 12K, the split tones will be adequate, since they'll be around 7K. Luckily, you're dealing with Duncans, so nothings gonna sound bad, even split. Personally, I like the sound of a full humbucker mixed with a split neck.
It's great for cleans.