The main thing I would research would be the utility of having the backhoe attachment on hand vs saving up jobs and renting a mini-excavator. There are lots of threads on OTT and TBN on that subject. From what I gather, Mini-excavators are an order of magnitude more capable on digging stumps and holes than the backhoe attachment. A job that would take half an hour with a mini-ex might take 4 hours with the attachment. The backhoe attachment for my L2051 is about $10k. I can rent a mini-excavator for a weekend for less than $500. Most of the long time posters on the forums believe it is better to rent an excavator. However, there is a thread on "What made you glad you purchased the backhoe attachment?". Considerations are, how far to the rental place and how often you need one. There is a lot to be said for having the tool on hand when you need it. How tall are you? The backhoe attachment seat is very close to the controls and if your tall and using it a lot that would be something to consider. I really wanted to have the backhoe but am doing fine without it. For your situation I would lean towards getting it.
Without the need to mow you would probably have the backhoe on most of the time. Since your only rear other implement would be a box blade, or better for driveway maintenance, a
land plane grader you will not be switching implements very much except for putting on the backhoe attachment. I have a rear finish mower, a rotary cutter (Bush Hog) a box blade and a
BigToolRack. I have a QH15 quick hitch adapter and rear hydraulic remotes to operate the Top and Tilt, TnT, making it much easier to switch between attachments.
On the other end of the tractor I would absolutely get a third function remote and a Quick Attach bucket. My
Wicked Root Rake Grapple by EA is my favorite implement and it needs the 3rd function hydraulic to operate. I also use my forks and a front receiver hitch plate. The quick attach vs pinned on bucket gives you the option to quickly switch from one to another front implement.
Tractor size - Some say that they like the smaller tractors for the woods to be able to get in tighter spots. The price difference between the largest B series Kubota and a Standard L series bottom end is about the same. The B series has creature comfort ergonomic controls. There are plastic consoles with cable operated controls vs long attachment rods. Even though I have only 4 acres I opted for the larger physical tractor without the fancy features. More weight means the ability to do more work, even with the same HP.
Engine size - Kubota engines with less than 25 HP meet tier 4 emissions without a DPF, diesel particulate filter. In order to operate a DPF there must be a computer and lots of sensors etc. If I had the need for higher HP I would buy a much larger tractor and dealt with the emissions. I must say that I have not needed any more power than I have with the L2501. Everyone seems to think that it is a sleeper. The same engine overseas is tuned to produce much more power but the one here is de-tuned and makes it's HP at lower RPM. Neither the front loader nor the backhoe attachment depend on HP of the tractor. For me it was no contest between the L2501 and the L3301 and L3901 sporting the DPF. I am more concerned about the electronics associated with the DPF than the unit itself. I just don't want error codes on a tractor.
You need the tractor Day 1. Yes your wife is the crazy one not you. She will reconcile this fact in short order.