Wow! If I give you some advice can I fish in the lake?
Just kidding, sounds like you have a fantastic opportunity.
I can personally recommend two sources who could do everything for you from properly repairing the dam to stocking/managing the lake.
Mel Smart, Smart Fish Farm in KY, but he spends a lot of time in our neck of the woods and has been a good source for me.
270 725 5622
Jeff Slipke, Southeast Pond Management, in Jackson,TN; also extremely helpful and knowledgable. 731 664 6355
I've had great experiences with both. Make sure you get someone who really knows dam/lake contruction to work on your lake-there are lots of guys with equipment who will say they can fix your dam, but you really need someone with experience with this kind of work .
Cost of stocking will probably be much less than fixing the dam, and will be very much dependent on how many, what kind, and what size fish you choose. As has been asked so many times on this forum, what are your goals?
Hope this is helpful, and good luck-you've got a great situation.