We've got a 4wd, 67hsp tractor with a loader for our farm. Between the mowing firebreaks, planting foodplots, logging, moving whatever, and etc., I feel it's a perfect size for our recreational landowner needs. You can put a small foodplot in with a tractor but it's difficult to put a large food plot in with a 4-wheeler.
Paying someone to put your plots in also assumes you can find someone that can plant when you want them to. Most farmers would probably consider your food plots a low priority over their own fields and might not get around to planting your plots in a timely manner, and sometimes timing is pretty important.
I'd stick with a tractor Pharmer and use a 4-wheeler for hauling out the big bucks and lots of does.