Here's where I buy my seed:
http://www.tomatogrowers.com/
I love the juliet for a small paste-type tomato. Sungold and sunsugar (as I've already said) are good low-acid tomatoes. They're gold colored. Snow white is a white tomato with a surprisingly good taste.
And if you want tomatoes for the rest of your life - yellow pear are open pollinated and will grow forever in that spot if you let just one tomato drop each year (seriously, they can be weeds).
As for trees indoors - the problem you have is with maintaining the right light levels. Plants are more affected by light than by temp (which is why the deciduous trees in my area have no leaves even though it's barely dropped below 50F). Plus, you have to have pollinators. A tomato will pollinate itself, but you have to shake it (with wind, or they sell - and I swear I am not making this up - special vibrators) or allow insects in your home.