That would really depend on your house temps and what equipment you are running. I live in Charlotte, NC, but keep my house around 72 degrees and haven't needed a chiller.
I guess a little more information would be helpful, thanks. I will be running three radion pros. I will be next to a window and a fireplace (I know not the best location but that's what I have to work with). House stays around 70-72 all year round.
You could always budget for it, see how the temps do when cycling, and if you need one pick one up. Otherwise you will have some extra cash in the budget for livestock.
I have a covered deck on the outside of the window so no direct sunlight. I also have plantation shutters on the window that will be closed all/most of the time. I am also planning using a material that blocks UV (LLumar) on the window-kind of like auto window tinting.
I agree that here in east tenn you should not need a chiller. Recently though,my ac went out and I wax scrambling looking for one. Luckily it was a very easy fix and was back to cool the next day. It's one of those things you don't need until you need one desperately...
I have an aqualogic 1/4hp chiller. It's basically like a refrigerator compressor, adapted to use for a fish tank. It doesn't have service ports, but any qualified hvac guy could put them in it easily if it ever needed a charge. It's not like the typical chillers that you can't charge or work on. I don't know what I'd want for it or if it's enough for your setup. I know I wouldn't expect to get a lot for it, since I can't use it. It wasn't anywhere near big enough for my setup and wound up heating up the room more than cooling the water, because it ran pretty much nonstop. I did have three metal halide bulbs though.