Advice for getting a JCP?

[sockSnek]

I've been thinking about getting a JCP for a while now, and there are 2 really beautiful yearlings at my local reptile store that I have my eye on. I'm not totally set one getting one yet because I live with Boyfriend, who has various concerns. So I'm looking to you guys for both ways to makes his concerns less concerning, and to decide what I should buy in preparation if he finally agrees to it.

Caging:
I'm looking at an AP T5 with a shelf. The care sheets I've read say 3x2x2 is a minimum, but I don't know if that's the minimum to make the snake happy or minimum to make the snake not-miserable.

1. Should I go bigger?
2. Can I get a divider with it and section off half the cage for a yearling or should I just go buy something smaller?

Heating (and Boyfriend's concerns)
So Boyfriend is kind of a furnace and is not ok with having another heat source putting several extra watts of heat into the house, especially in the summer. Right now I have a UTH for my corn, and I don't think it makes much of a difference in the room temperature, but he seems convinced it does.

1. What are good options for heat for a JCP? I have a CHE that's not in use, but I'm thinking about trying an RHP.
2. Can anyone with an RHP talk about their experience with these?
3. How much more effort will it take to keep the enclosure at a good humidity level if I use a CHE?
4. Of the acceptable options, which ones will add the least amount of heat to the room, and is there anything I can do to make it even less?