I ran a 9spd chain and it worked OK for a while, but I ended up breaking it multiple times in one ride on some high torque, low cadence efforts - switched to a cheap KMC single speed chain and I've not had any problems since. YMMV.
KMC Z610 for me. It's a bit heavy if you care about that sort of thing, and it's sometimes hard to get into a smaller chain tool. I had to hammer it into mine the first time which spread the tool a bit and now can put it into place by hand. It's a bit hard to find, but is a 3/32" chain unlike a lot of the other heavy duty KMC chains. With cheater links too.