Nordstrand makes a side-by-side J type, also. As does DiMarzio.
I had the DP123 Jazz set in my MIM-J fretless, now owned by another TB'er
These are very J sounding, and avoid the single coil hum.
My on-order Warmoth fretless P/J uses a Nordstrand BigSplit in the bridge position. It is a side-by-side split coil type, for hum elimination.
The split coil and stacked coil types are a smidge less bright than a single coil, so there is a trade-off to get rid of hum.
There is an excellent tutorial here on TB for doing a proper shield job.
This will go a long way to quieting the single coil hum.
I saved as a PDF when it came out, but I'm sure it can be found here with some digging.
He shows how to do copper tape, etc. Lots of pix, very nice tutorial.
If you go this route, consider using a star-grounding system to avoid ground loops.