I pay to have mine ground out when you see the machine that does the work you may have second thoughts about doing this yourself.

With that many stumps, although not large stumps, you'd be better off with one of the larger stump grinders. It would be a self propelled unit. But if you do not have experience with large machinery, I'd call someone in to do it. These things can be extremely dangerous. People die operating them. Expect to pay ~$300/day to rent one of these machines for the day. You'll need a hitch on your vehicle to tow the trailer it will come on. The little walk behind HD stumpgrinders will run you ~$75/day. They will beat you up and it will take probably 2 days to do all your stumps.

I recently ground about half a dozen fir stumps using a walk behind rental unit. The largest was probably 24". It took me about 2 hrs of actual grinding time. (cost was about $75)

10 stumps will take you about 4-5 hrs. Time goes up expontentially based on the diameter of the stump.

Wear hearing protection, safety glasses and keep people and animals away from the work area. These things spew out chips in all directions. It's still very hard work because you're constantly manuevering these things.