FindAWay.... welcome to HSBBW!
There are so many JUCOs that do a good job, I'm sure you'll receive lots of suggestions. You are on the right path though with your questions.
Tennessee has I believe 11 JUCOs with most of them fitting the description you've given. We have lots of TN posters and some have had kids play in schools there, so if you end up with a particular place you're interest in, you might want to post about that school.
My college son was going to originally go to Hiwassee in TN, which is a WONDERFUL school with a young coach that doesn't have a lot of experience, but is prooving himself and is a wonderful person. The school was having some credentialing problems due to income reserves, nothing academic. I don't know where that stands, but it might be worth checking out. I think once they can clear up that issue, the program stands a chance of growing in a wonderful direction. The best people we met in the college process were at that school.
We also met and visited NW Shoals which is in Alabama. Another school that isn't talked about alot, but a genuine and energetic young coach. He's on top of their academics and participates hands on in that department. Let me know if you might be interested in that school as we have a poster with a son there that could give you inside info, I'm sure.
Louisburg in NC is always a top ranked JUCO, but it carries a very large roster with a JV. The assistant coach there is a guy who's one of the most awesome coaches around in my and my son's eyes. I think it would be a great baseball experience, if your son would play.... lots of DNF guys as you've already mentioned.
I see you're in Florida and of course Florida has some great JUCOs, but again many DNFs. I learned from my son's one year at a JUCO that the important things to look at are not only where kids go on to play, but look and see if those kids are contributing where they play. Just because a JUCO is good at placing kids at a large DI doesn't mean that kid is valued there. Also look at the size of the roster. If a JUCO is carrying 35-45 kids, remember that's a two year school and a larger roster than a four year school would have. No way many of them will be playing. Many JUCOs have arrangements with DIs and particular scouts that "their" kids will play if they're sent to that JUCO. Something to discuss with the coach up front and obviously something to do your homework in regards to.
Good luck to your son and again, welcome to the site.