I have both a yellow ackie (adult) and a B&W tegu (juvenile). It's a tough call! They're both great little animals. Differences between the two that I've personally noticed: My tegu is much more voracious than my ackie was at that age. He's also much more curious about me and more interactive. When I open the tegu cage, he comes running over to investigate. If I put my arm in the cage, he climbs on it. If I put my hand on his basking spot, he'll climb up on it to bask. My ackie will watch me from his perch and occasionally wander over to see if I have anything good to eat when I open his cage. Ackies will be easier to care for as adults. Tegus, like larger monitors, like to soak and defecate in their water tubs, and the tubs have to be hauled out and cleaned at least once a day...or the tegu has to be taken out of his cage to defecate. Tegus also have a tendency to have some sort of wild rumpus in their cages fairly regularly that will leave substrate everywhere, water dishes fouled, and cage furniture overturned. Both lizards are very entertaining to watch, however, and I would be hard put to choose between the two of them. It does sounds like you're leaning towards the ackie.
