Guides have a hard enough time making a living on a lake that has produced the last two state records like Fork. You fish every day for 4 months then you pick up trips when you can the rest of the year.
Having been one, you have to go where the folks want to go. Lake Fork is about as good as it gets in NE TX. Guiding is a tough way to make a living even on a lake with world-wide notoriety like Fork.
If you are dead-set on going to a lake near Waxahachie I would suggest you look at Bardwell or even venture out to Cedar Creek and even then you I would bet you will be hard pressed to find a guide on one of those two lakes.
If you haven't been to the Texas Freshwater Fisheries Center in Athens I would highly suggest that as an activity for you and your BIL. It is a world class facility and its only about an hour away from Wax. Let me know if you decide to do that and I will arrange a back of the house tour.
I have friends in low places.