I have found that Benstonei, Belli, and mirabilis Thai are all fairly small (or slow) growers that love lowland temps, but Bicalarata, Ampullaria and other mirabiis are much faster growers and may become to large (except amp as they take to pruning well).
Ventricosa are also happy in lowland conditions, even though they are found above 1000M, again they are fairly compact, otherwise if you have some experience Campanulata and Pervillei have been doing well in my lowland conditions and again are pretty small/slow growing.
Others that thrive in lowland conditions for me are Khansia, alata "Luzon", albomarginata, distilatoria, rafflesiana, gracilis (but this would be a terrible terrarium plant), Kongkadana, most Maxima, most veitchii, Truncta and Mirabilis "Globosa".
Otherwise Campanulata X ventricosa does very well and stays small, and Ventrata could be trimmed back, as could Maxima X alata and Rokko, but eventually Maxima X alata and Rokko will outgrow the tank.