There is lots of good info & advise on this thread regarding heavy equipment. On thing not discussed is the difference between a dozier & a crawler. IMHO, if a guy is going to buy only one piece of equipment, I would choose a crawler somewnat like this:
It's kind of small mid sized, 85HP, has a clam bucket & rippers. This allows you to carry dirt & load it in a truck. It allows you to pick up trees The rippers let you dig hard packed clay, then push or pick up. I think Cats are the top of the market, then JD & Case kind of in the middle. Komatsu is in there somewhere, but I'm not very familiar with them. I can easily get parts for this 1975 model. One other important issue is how to move these things. If you stay under 20,000lbs, you can move them yourself; otherwise, you have to hire a big rig(expensive). And you will need to move it to at some point to get it worked on. So, if someone is hellbent to own one, this the type I would recommend...du
