Sorry to hear about the loss of your natives. When you get back, I highly recommend the native Blue-Spotted Sunfish. They stay much smaller than bluegills or pumpkinseeds (about 2-4"), and color up a really nice cobalt with iridescent spots. I haven't kept the bluegills myself, but I suspect that the bluespots don't disrupt the plants in the tank as much, either. Here are some pics of mine:
