Sounds interesting and good luck! Do you really need a co-founder? IMO, if at this stage you're paying someone a "reasonable hourly rate" they aren't really a co-founder but rather employee #1.

I know it's popular right now to have co-founders, but I'd say just stick with it and go for it. If you have clear tasks and the revenue (or funds) to support bringing on employees the do so but otherwise put your head down and stick with it!