Not a fan of the APP choice for this combo. With the shields, buffs and heals, you'd be better off investing in one of the villain epics to get the pet. This way you can solo higher levels with a well-protected friend. Then, if you get into incarnates, you can pick up more pets and have them buffed as well.
Thermal is useful for teaming, so for those times when you're solo or on a small team, having the ability to toss pets out there would be a great strategy.