Try the magnets first. The Hybrid is a fantastic pickup in an HSS, though, as it is hot but not hot like a JB, and has an open, scooped sound that blends well with singles.
i use a custom with an a3 magnet in my hss guitar with a pair of aps2 singles and i really like the combo
After reading the descriptions for the custom and C5. The custom with the ceramic sounds like it might fit the bill.
Anything specific I should get for ? I know there are smooth and sandcast magnets etc...
I like a Custom 5 in an HSS setup... but even better the 59/Custom hybrid allows you to split to the strong slug coil (wound like a SH-5 Custom) so your 2nd position will balance better with the single coils. If you're not doing any splitting I recommend something lower output like a 59 to match the output of the single coils better.
Assuming the 5 means Alnico 5....what mag is in the Custom