Grippy Featherweight Wheels

I'm currently building my first featherweight, and i'm looking for some suitable wheels, i'm needing the grippy rubber sort, or something just as good grip wise.

I need at least four, but I'll buy up to six if you have them at decent pricing, as i may opt for a 6 wheeled contraption, else just have two spares. I know someone on here was planning on creating some to order, but I think that's still a way away.

No immediate rush, as the REC gearboxes I need are out of stock currently, so waiting for them to have 4-6 of them too!

Let me know if you have any going, and what price you'd be after.
Cheers!