I took a drive with my wife to Lake Palestine to scope the area out. The "Deep End Boat Launch" was a nice low-key twin concrete ramp with plenty of parking across the street for your rig. No services were in sight except some trees throwing shade here and there. We then drove up to Salina Bay RV Park. We felt that place wasn't for us and our equipment. I think it may have fallen on hard times since you last saw it.
My wife is looking for a place on Lake Palestine where we could stay and have both ample parking and convenient water access. We don't do the RV thing, just tow our boat around for good times. If my wife should find some adequate accommodations I'll let you know.
What kind of boat will you be putting in the water?