Earthquake mentioned a Peavy, which is the tool with a pointed tip on a hinged piece of steel that you use to roll a log.
As to the stump grinders. The toro is OK at first, but the teeth dull way too quickly, especially if you want to go a little deep, deep being beyond about 6". You definitely would want to buy teeth when renting, and could look to see if the existing teeth haven't been fully indexed yet. I think I paid 45 bucks for 3 teeth, but that was awhile ago. The good news is that most people don't know you can index (rotate the tooth for a fresh edge) a couple of times, and you can tell by looking at them. The 339 one day rental you were quoted was for a more serious machine, probably around a 15hp bluebird, and is in line with what I have paid for that more serious grinder. I think the Toro was around 150. With that many stumps, I'd pay the difference, but that's me,, after having gone both routes. I would also explore getting the tree company to discount the grinding. It's probably the easiest part to negotiate, price wise, but don't expect a miracle there, either.
Sorry for your troubles. Been there, done that. Sucks.