I have no idea how much experience you have with grinders, but if your thinking about a skid steer and grinder for 2k acres of trees, you might want to ask far more questions, before venturing forward with the idea. Just how many tree's per acre are you talking, what size in diameter, and height are you working with, what type of terrain are you in, whats the time frame to get the job done, how fine of a grind do they require, is there a requirement to equally spread out the mulch or just as its ground. Are they offering you a contract, any money up front for expenses and about a couple dozen more questions and have you chatted with a banker who will fund you till the first money comes through and have you had a lawyer overlook your contract to figure out how they can back out and leave you hang.
Horsepower grinds tree's, your looking for production, not a skid steer and grinder head on that, as for fecon, rent it short term before ever signing any long term lease, then before doing so, hunt up something worth taking home you can afford to run and keep going, that makes you money, not the manufacturer. There are far better makers of grinders out there you'd want to consider long before fecon, do some checking around, and make sure you have dedicated power to any head your running, not robbing hp from the carrier unit.