Barringer i am in your boat a bit. I can train my kids. Triplets are nine years old and started tournaments this year. Twins are 3.5 years of age and have started hitting. We train four or five days a week, play junior team tennis, and dont do privates or clinics. If they show promise i will travel a bit but i feel we have enough competition in the south( knoxville) not far from atlanta. Im not going to chase points when they r young.
Don't forget to let your children expose to other sports, music, art esp when they're young. You have a set of triplets and twins so chances are one or more children might enjoy or has great potential in another area.
Besides my full time career I am also an accomplished piano player. I can teach my 2 children and save money but chose not to. When they were young, they were given opportunities to play different sports, learn different musical instruments, exposing to dances, art, etc. My 19 yo chose to carry on tennis and a few things till finished up her high school while my younger one enjoys mostly tennis. They both excel in their on individual way.
The point is even though tennis might be convenient for you, if you can afford it, let your children expose to other sports, music or other areas. The one special gift that (at least) one of your child has, might then be discovered and nurtured.