I'd call the NRCS and ask for a list of local dozer operators. From that list, I would ask for references. I would contact the references and ask if I could come and look at their work. There is a lot of difference between digging a hole for fish to live in and grubbing mesquites, working on housing sites, etc. I would ask about rate per hour for dozers, sheepsfoot rollers, and possibly trackhoes. I would also check with the NRCS to see if they would lay out the site for you.