If you go 75 and are willing to stay in GA, there is a nice one called Eagle's Roost in Valdosta, GA. It's off exit 5, on the east side of I75. It's a very nice stop-over; we've stayed there 4 times on our trips back and forth to FW from North GA. Bear in mind, it's literally right off 75 so you do get a lot of highway noise...however if you're super tired (like we always are when we get there) you won't notice it. There are large pecan trees throughout the site so you might also be listening to pecans fall on your RV too.
The big plus to this place is that there are 2 RV dealerships with parts departments that are very close by, in case you need them. This past October we blew a tire while driving down (less than one hour from home) so it was nice to be able to get parts when we stopped to fix all the things that fell apart/off as a result of the blown tire.
The people that work there are super nice. It's really a nice place. It's about a 3 - 3 1/2 hour drive to FW from there.