Roy, the exchanges about R1 v. R4 tires, and filled v. not filled, got started in jest, but believe it or not, you'll probably have to make a decision in the end about those issues, at least if you opt for a frame larger than a subcompact. For now though, stay focused on what make, model (especially class/frame size) and dealer you want. You can start another thread when have to choose tires, remotes, quick attach loader bucket, etc.
The folks who suggest that you not neglect the attachments/implements in your budgeting are making a very valid point. A tractor, big or small, is useless (except as simple transportation) until you factor in the attachments/implements. You can't go wrong if you work backwards from the attachments/implements you are likely to use in deciding the make and model of tractor you want to purchase. If you're going to use your loader a lot, you may be alot happier with 6' wide bucket that can lift 1,500 lbs., than a 4' wide bucket that can only lift 800 lbs. Similarly, if you have a lot of grass to mow, you'll be glad you got a tractor that is comfortable with 5' or 6' mower deck, than one that is limited to a 4' deck.
In my case, I could have selected a small or mid-frame CUT to power most of the implements I was going to use, but when I figured out that I would likely get a back hoe attachment some day, my thought process changed. After studying the specs on the various BH attachments, I realized that only a large frame CUT would accommodate the particular BH attachment that I would eventually purchase. When I had the attachments/implements and class of tractor figured out, the HP choice became just an afterthought.
What ever you do, pull the trigger soon. We're wearing ourselves out spending your money for you.