Tegus ROCK! I want to keep them too someday, and am currently researching.

1- blue tegus are smallest and thus require the least amount of space. It depends on if you plan to build, or buy an enclosure. The cheapest seem to be cages made from livestock watering troughs made from galvanized steel. You can buy them at farm supply stores and they come in 6'.. maybe even 8' sizes.

2- tegus will eat a lot. Reds and argentine B&Ws require fruit high in vitamin C. Blue tegus are strictly carnivorous.. and smaller, so are a bit cheaper to feed. Most say UVA/UVB lighting is required, and tubes must be replaced every 6 months. Shop around for prices on those though.

3- I don't think they worry too much about the hibernation. I'm not so sure about this though.

4- Go here (awesome tegu forum/website): http://thetegu.com/ There are care sheets in the 'helpful info' page.

5- Tegus are VERY personable, and make a wonderful pet. I even hear of some that literally beg to come out and be with you! I can't think of another reptile that actually enjoys being touched. Babies can be scared though, so need to be worked with.

Here's a quote from one of their articles:
'There are several levels to a tegus 'tameness', from being able to tolerate human contact to actually craving contact with people. (Note: My tegu responds by name, taps the enclosure walls when it wants to be held, walks to my hand when its in the enclosure and nudges me, loves to cuddle against my head/neck while on the back of the couch, etc.)'

Good luck!