Because of the lay of the property, it doesn't look like there would be a whole lot of earthworks involved...mostly just dam construction.
Usually the dam material is excavated from the bowl portion of the pond. So your depths would be even deeper (or some of the shallow areas made deeper) to obtain the soil needed in the dam. Even if clay is hauled in for the core center of the dam, likely the only economical way to provide enough material would be for most of it to come from on site.
NRCS guy can help you with recommendations on all that, including your soil type being suitable for dam material.
If I were you, I would take a drive or look on Google earth for ponds in your area. Find out who the owners are and talk to them. See what they did, how it worked out, and who they used for contractors. Learning from your neighbors mistakes might save you from making the same ones.
Lot of good ideas here on PBF, but no substitute for someone on the ground, in your specific area, knowledgeable with the conditions you will be working with.
