From a cost perspective given your size and now I know your animals you intend, you might consider cattle. Buy three steers that will set you back roughly $2000.00 and a custom fitted scythe. Work them a whole season. They will mow and fertilize your pastures and you can sell them at the end of the season for a profit. They will improve your pasture better then a mower ever will and will make you money. Stack that up against a mower that will cost $3000.00 and will have to be fueled and maintained and will eventually break. As you can tell I have an aversion to machines if there is any other way around a problem. They are an easy solution, just not always the best.
If you plan to keep hogs they can be quite destructive regardless of the breed. They are great for tearing up undesirable plants, brush and small trees. But if you have decent pasture now it may be a step back letting them out to be destructive on decent land. My opinion. They are woodland animals not really grazers.