Paul -
One way to save a few bucks would be to rent a decent sized tractor for the initial clearing, dirt moving and heavy brush cutting... probably in the 30 HP range, with FEL (and hopefully a toothbar on the FEL, though I've not seen one on any of the rentals around here). A backhoe might be nice, depending on how much digging you need to do.
Once the grunt work is done, you can step down to a smaller tractor for the longer-term stuff. If you've got many hills and/or muddy areas, you'll probably want to look at 4WD, but you can get a lot done with a decent sixed vintage 2WD (Ford 8N, for example). If as you say the Kubota BX series is on the small side for you (which I would agree with, given your existing mowers), you could look at something in their B series, like a
B7500. In NH line, I'd look at the TC18, TC21 or TC24 (the 24 would let you run a 5 ft bush hog. The 18 is probably better suited to a 4 ft. The 21 might run a 5 footer, if you're not pushing it too hard). JD look at the 4100 or 4110. (4200.4210 if you ever envisionn getting a small backhoe).
In the used market, look for the Ford/New Holland 1710 or 1720. These are very similar to the NH TC30. The engines are just a bit smaller. THey would probably handle your initial clearing/dirt moving needs, as well as your longer term uses. You could also look at the Ford 1510, if you see one around. These are more recent used, as opposed to "vintage" tractors. There are some Kubotas running around of similar age/capability, but I can't remember the model numbers. As an example on price: there is a Ford 1710 (26 HP) for sale here in Vermont with 420 hours ("young" by tractor standards) in "excellent condition" (according to the seller, I've not seen it) for $7900. He's also selling an "almost new" 64" Puma snowblower for $900 or $8500 for both. If you are interested, I can send you the phone number and/or find out more info for you. Let me know. (This is exactly what I was looking for a few years ago, but could not find one, so ended up buying a new TC33D).
John Mc