please consider hiring, renting, or purchasing (then sell it)the "yellow iron" to get the big dirt work done. It will be much more cost efficiant.
Your 27 hp tractor will have plenty to do after the dirt work is done. years of mantanance lies ahead of you mixed with good fishing.
I have put 3 tanks on my place, with the 4th in the planning / dreaming stage. Yellow iron put it in, my little orange tractor keeps it going.
Lots of blood, sweat, tears, smiles, victorys and defeats....fun, fun, fun.