Kevin (on the site here) has a very nice sheff in a viv right now. it acclimated very well. the root structures on it are great and grow fairly readily. you could shoot him a line for some info.
kevin@tropicalinhabitants.com
i have a few ficus benjamin in vivs. theyll grow out of the top if you let them. they grow pretty fast once established, and would make a nice bonsai if properly trained. they also form some nice ariel roots if kept in very humid conditions. ill try and get a few current pics of them.
ive never tried bonsai in a viv for one of the reasons Tindo stated. its hard to get every where you need to when your tree is constricted by a glass box. if you have a large easily accesable tank i dont think anything is out of reach. definatly get some pics up when you get it. ill post my ficus pics. even though they arent bonsai-ed you can get a feel for whats possible inside a viv.
oh, and as far as drainage, the ficus dont seem to need any more drainage than any of the other common terrestials. they do need drainage, but moist soil isnt going to kill them.