Someone with more electronics experience would need to confirm this for me. But I'm sure those motors would be way better off with much higher than 30v. They'd probably be happy with around 80v. However, your driver board probably couldn't handle it.
When I switched from a Xylotex driver board to the Gecko G540 and a 48v power supply, it was the difference of night and day with how my motors ran. I was always having problems with resonance at certain speeds, and the motors would suddenly stall for no reason at all.
I'm guessing those motors would like a higher voltage then even a G540 could give them. If you wanted some decent performance, I'd buy the motors that CNCRouterparts sells and a Gecko G540. Their motors are matched quite well to the specs of the G540, and you'd have excellent results.
Edit: Those motors you are looking at may be cheap, and that's exactly what they are. Round body motors are not recommended. I think it had something to do with losing their magnetism after a while or something. Plus, those are only .18 amps. Very, very wimpy little motors. Spend some money once and get a gecko, and I promise you'll never, ever, regret it. As someone else mentioned, the poor can't afford to be poor.