Hi!
If you were to get another betta, just consider the upgrade he'll be getting from his silly little cup to the critter keeper!
The big thing with a tank that size is obviously the temp... the tanks i have are all at least 2 gallon - and the heaters I use are the flat stick-on-the-side-of-your-tank Hydor Mini Heaters...
HOw warm is your house? I'd say if he would be going into a 1 gallon keeper, just leave him at room temp unless you get down below 72 degrees. If you do go lower than that, I would consider skipping it, or getting a bigger tank to put him in besides the 1G tank. That can always be a tough one with heating...
And as for animal emotions - I think they really can feel emotion, and probably even jealousy. For instance, I have 2 tanks side by side at work. One has Jasper in it, one has Charlie. They both are the idential sized tanks and have pretty much the same stuff in the tanks. Whenever I"m paying attention to one of the boys, the other one will stare at me with his fins drooped staring. I don't know if he's having fun watching me look like a big ol' tard talking to the other fish, or if he's supremely jealous of me spending time talking to and playing with the other fish. I'm just not sure.
ALSO.....
With my (RIP) little boy Amos, I know he loved me. He, to date, is the only fish that would genuinely be beyond happy when he saw his momma show up for work in the morning,or at any other time for that matter.... He would always flare at me when ever I appeared - whether it be that I went to the Diet Coke machine and was returning to my computer, or I had been gone for a long weekend. There were SO many times when he swam just as fast as his little fins could carry him over to the side of the tank where I was, flaring on the way because he was so excited to see me. I miss that lopsided little flare every day. I wish my other boys would adore me that way, but Amos was just special. He too, along with my other 'misfit betta crew' probably knew that only I could really love him unconditionally - with or without their little flaws.
Man, I miss that little boy every single day.
] and move the new betta to your night table! 
