Flame, I'd go with rye, if the temperature will allow it to germinate, then go with Bermuda for a permanent cover. Besides it's almost weed like growth, it handles most common broadleaf herbicides very well. Plus, the correct herbicides can be applied when the Bermuda is dormant, or actively growing, your pick.
Also, Bermuda can chase the waterline down if you have summer water fluctuations. When the water level hopefully returns to normal after the spring rains, shoreline aquatic weed growth can be greatly diminished because of the established turf.
As has already been mentioned, turbidity should ease with a good ground cover on both the water shed and pond structure.
IMO, Buffalo grass is harder to establish, and does not accept certain soil types as well as Bermuda. Plus,it does not like herbicides while it is actively growing. Weed control most likely has to be done while it's dormant, which restricts control of summer weeds.
Just my 2 cents.
