Go with a 3/4 ton or 1-ton truck preferably with a 6 cylinder in line diesel, just my preferance folks.
In all sincerity(sp), buy more truck than you think you will need sooner or later you will be using it. Sure the half ton can tow it but as mentioned what about when you are towing the tractor and you want to haul some dirt or a few bales of hay.
Read all the posts about those that have under tractored themselves, the same holds true with a truck. I have the truck I just need the tractor, hopefully a nice L3110 or JD 4310.
Besides this is America (some are in Canada but it still applies) bigger is better!
steve