I'm in large part a single coil purist so I think that's a great decision

Then again- when I am in the mood for humbuckers I seldom prefer them in the neck position, so I find HSS a good compromise. But if your playing is clean/surf all the way, a bridge single is what you probably want. Or your can try something like a Duncan Stag Mag pickup, which has genuine Alnico pole coils (like a single) that split quite well. I even like the 'full' tone of that pickup, but it isn't really a typical humbucker tone; more like a Fender Wide Range pickup.
I've experimented with a few split humbuckers in combination with a middle pickup; while it's true not all pickups split well, I had good results with both higher output & lower output pickups across the whole range. My stock American Deluxe pick guard was wired HSS- I still got a pretty decent split tone out of the stock Fender humbucker, a fairly low output A2 thing at like 8k DCR. Height settings also impact the sound. Higher output pickups (like a Duncan Distortion) actually split quite well too.