An older farm tractor might fit your needs if you don't need the 4WD.
A wide front end is almost necessary for a front end loader. I have
seen tricycle types with loaders though.
Some sources: Ebay. Big Iron. Fastline. Tractor House. There are
many more online of course.
Our irrigation set up crew had a Zetor, made in Czechoslovakia. I
think it was a bit crude but it did the work. He was satisfied with it.
There is a website called TractorData.com that might help your search.
Another would be
yesterdaystractors.com Still another would be the
Nebraska tractor test lab.