In need of some help

[capt_howdy]

Hi All,

bunch of noobish questions for you guys.

ive been going a little nuts with trying to figure out what kind of enclosure to get for the corn i intend to get at the expo in mississauga next weekend.

I wish to start out with an exo-terra viv. either the 12x12x18 or the 18x18x18.
im not concerned with having to buy a bigger tank later.

for heat i would like to use a UTH. i cant keep the light going all the time or i will end up with complaints for the people i live with. any recommendations for the equipment i should get?

as far as substrate. i love the look of the bark but i keep hearing that aspen is better but i think it looks it belongs in a hamster cage.
has anyone had problems with the bark? is there anything i should know?