Greetings Ms Larson (and hello Rich... D-3 basketball is different in Colorado where I assume Loveland High School is located.)
This previous 7 pages of this message board have the advice that has been given by many posters to several parents. The message is still the same.

1. Your son needs to go to a campus where he would feel at home, were he not playing football. Does it offer his degree plan? Does he like the feel of the school? Does it seem like home? Is the financial aid package that he can get within his/your budget?
2. If he is not going to play much in the first year, do they have a JV program that brings him into the system?
3. How close to home is it? (Of course, Baytown, TX to everywhere else is several hours drive in D-III.) Is that even a concern?
The thoughts of playing in a competitive conference are excellent. Winning and playing competitive football make the experience more enjoyable. In fact, winning a conference championship in a less nationally competitive conference is a fair consideration, especially if he is getting plenty of playing time. The American Southwest Conference is one of the best 5 D-III football conferences in the nation. There is very little in NAIA in the state, and Dana and Concordia NE are all NAIA in the Great Plains Athletic Conference. Peru State is an independent NAIA school.
Don't be fooled by the term, "athletic scholarship".
Price the entire package. He may be able get a better aid package that does not include an "athletic scholarship" at a D-III than the package he would get at an NAIA or D-2 school.
Out of state tuition for a Texas resident is likely to be as expensive in Wisconsin as private college tuition in Texas, all things considered.
D-III is not "high school" or "glorified intramural" ball. Most teams have D-1 and D2 transfers who played at the other levels and moved to D-III for many reasons not related to the sport.
As a Texan, I am proud of the competition in the ASC. Please look here first, because he will see many of the players against whom he played in high school playing in the ASC. All of the ASC schools do a good job of preparing student athletes to compete in the real world. Almost any other poster can validly say that same thing about their local D-III conference and teams, including the SCAC fans at Austin College, Trinity, Millsaps, and the new program at Hendrix in Conway AR. Almost every successful program is geared towards retaining student-athletes on their way to graduating. (If he is looking at coaching/teaching as a profession, then the ASC experience will be invaluable. Coach Hal Mumme, formerly at Head Coach University of Kentucky and New Mexico State, felt the appeal to returning to Texas to coach as one of the things that brought him back to Texas and to McMurry.)
Thanks and email me if you have any other questions.