"The fundamental importance of TRACTOR WEIGHT eludes many tractor shoppers. Heavier tractor chassis weight is more important for most tractor operations than increased tractor horsepower. Bare tractor weight is a tractor specification easily found in sales brochures and web sites, readily comparable across tractor brands and tractor models, new and used. "
^ If you haven't worked with these classes of equipment before, it can be challenging to fully appreciate just that one paragraph of Jeff's.
From another world..... if you were going to throw a total newbie into a rugby game, who's more likely to end the game less damaged ? The fit 120# guy, or the fit 260# guy ?
Second to hands-on experience...... take the time to wade through the excavation (and repair) threads on here.
Light FELs esp. are not designed for dirt excavation, you'll see more than a few examples of damaged FELs doing heavy dirt work. Contractor neighbour retired up north of here.... before he moved, he set himself up with a really nicely overhauled older Ford backhoe - rang in something like 15k#.
You can't change the pace in a competitive rugby game..... you do have time on your side, from your description. If you read through the threads where people have successfully used smaller equipment, carefully note (or ask) how much operating experience they had going into the project.
Operator skill AND patience can compensate for lesser tools to some extent, but at some point there is a limit - you are not going to break a 50# granite rock with a tack-hammer. Pass those limits, and damage will occur, and sometimes not just to the equipment.
At this point, you don't know what you don't know..... :thumbsup: for asking. If you do go with a lighter unit, be prepared to justify to SWBO why early repairs are needed

(Plan Worst, Hope Best).
I'd lean towards contracting out the heavier stuff (ask around, plenty of guys work for cash, and if you can live with somebody else's schedule, you may find a deal you can live with), and selecting a lighter unit primarily for the lighter/later maintenance tasks.
I have relatives down-east who have (almost literally) countless tractors on a multi-generation farm. When they need something heavy done, they just write a cheque for the dozer/hoe work.
Rgds, D.