I will tell you, I was going to tackle the dirt work of my road with a 100hp tractor and a 6yd dirt pan. After doing a bit of other dirt work, I recognized that, over the course of the project, I would likely spend the same $$$ on diesel as I would on a dozer rental.
I went with the dozer and I am very glad I did. I had never operated one before, and it took a little bit to get the hang of it. But it was well worth it in every way. I moved more dirt in one pass than I could have done in an hour with my tractor.
My recommendation is to really look at the thought of a rental. I had it delivered, which wasn't cheap, but obviously was the only way to get it to the farm. If you decide to get it, don't get one which is too small. After talking to a lot of excavating contractors, they ALL recommended going big, ie D6K, rather than a smaller D5. They said you could certainly get the work done, but when you are renting, the little saved in $ up front costs much more $$$ in time required to have it on site. They all recommended getting the "K" version which was a hydrostatic trans. You simply push the stick forward to go forward and pull it to reverse. No 'shifting, gears, etc'.
My final recommendation, if you do this, is the same as one guy told me... "just crawl... keep it slow... you will get it done and done well and make fewer mistakes that need fixing". I'm glad I did, because while a 6-way blade can be learned, there is definitely, as I found out, a learning curve in putting it where you want to get the results you want.
Oh... and one final thing. Get them to show you how the 'floating blade' works and how to use it. I didn't know it even existed... and most of my 'fixing' would have been solved had I not been 'gouging' while trying to simply clear waste.
I rented from Whayne's Cat in Lexington. They were great. If there is one near you, I would recommend it, very highly.