The good thing re: feed is you have a pretty good feed store nearby in Pleasant View Mill (I assume they are still open). Their offerings have changed over the years, but they carry several national brands. They are also handy to pick up a few bales of hay if needed.
Ashland City has a Co-Op, but it didn’t used to be very well stocked for horses (some Co-Ops have better equine departments than others). It had basic farm essentials.
Ashland City also has a TSC for farm essentials.
When we first moved to TN, I fell in love with Ashland City and wanted to move out that way. I tried to find boarding in the area and learned there was absolutely nothing at that time. Maybe that has changed, but I’m doubtful. I know you will have your own place, but just sharing because it is helpful to know.
TN Equine will do farm calls/emergency services for the lower part of Cheatham county, but I’m not sure how far north in the county they will go, as it’s quite a ways from their main and satellite offices. They will go almost anywhere for scheduled appointments, but I personally always want access to emergency farm call services. Maybe there is an equine vet in Clarksville who services the area?
I had the best hay guy. Not cheap, but reliable with access to excellent hay. PM me if you want his contact.
Farriers can be tough. Mine came from Kentucky.
I really would consider investing the schools for your son. I have worked in education for many years and have friends teaching in Cheatham. They are better than they seem.