Turns out the Behr rims I scored on eBay were brand spanking new, and had new rubber on them SO... gonna have to wait till I burn them off till I try new tires.
Lookin' at the following tires:

Heidenau K73s

PerelliMT60Rs

Maxxis Presa Rear Supermoto Tyres


Goldspeed Rear Wet Supermoto Tyre
Which one do you like? I'm still leaning towards the K73s, even though they supposedly get only 3K in their lifespan.