If you build an upground reservoir type pond as noted: "build up a big berm as high as you like, and finish off by lining the sides and bottom with compacted clay. You could certainly do a 10-12 foot deep pond in that fashion."
Those type of empoundments often leak through the embankment wall because the berm was not enough compacted the best way using a form of sheepsfoot roller - large heavy knobbed form of equipment designed specially for best soil compaction.
Maybe even consider down sizing the pond to 0.7 ac if there are benefits to that smaller size of pond for your situation. BIG high quality fish can certinally be raised in 1/2 - 3/4 acre of water when it is managed well and does not leak.

Thus you want to take extra steps to get the basin and embankments VERY WELL COMPACTED. Maybe even have them use or rent a vibratory sheepsfoot compactor that is especifically designed to be the best method for compacting soil/clay. That is why those machines exst. If it were me, I would for a type of no leak insurance, also utilize and incorporate into the basin some of the enzyme soil sealants such as SoilFoc during the construction phase. A leaky pond is a big headache. Just look at all the leaky pond threads on this forum. Trying to fix a leaky pond can cost as much as it did to build the pond.
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=575123&page=1

Before commiting to construct with a contractor, I would be contacting Michael Gray middle TN expert and well experienced pond builder for an expert second opinion. He writes articles in about every PBoss magazine many of them about building ponds dealing with bedrock conditions common in TN.. Tell him Pond Boss Forum suggested him to you. You will get the best bedrock basis built pond from him.
mgrancnstruction@yahoo.com