I would go with a rye grass/ rye mix.
Wrangler is the only bermuda grass sead the NRCS will plant in southern Ok . I have used it one time with pretty good results.One thing about bermuda if you just get some started here and there it will spread pretty quick. You can also spread bermuda hay and it will come up through it and won't wash away or dry up as fast.
This is speaking as a rancher.
Any cover , rocks , brush for fish is a lot easier to put in before the pond fills up . I found this out the hard way.