Not to burst your bubble but I recommend you check Alabama Division of Wildlife and Freshwater Fisheries Regulation 220-2-.26 before buying anything. Nowhere near the limitations we have here in Florida, but there are definitely limits on what you can legally have...for example, no White Sturgeon allowed only native occurring sps.
Good news though, being spring fed means the temperature is likely constant. Figure out the base line and you might be able to put some of the hardier temperate neo tropicals in your pond. Enjoy.