TearDrop campers are awesome, mine has a queen size bed. But I wouldn't be comfortable with a large dog and a small child inside with me and the wife, one of them I could do. You can get a TD with a king size bed but even then you might grow out of it. With your budget you might need to look...
I wanted a RTT for a long time until I stayed on the top bunk in a cabin on a fishing trip last spring, my feet cannot handle the climb down in the morning. I currently use and really like my tent cot, keeps me off the ground, biggest drawback is limited space inside. Looking to build a trailer...