Several different sundews and butterworts will do good in a terrarium if you have good CFLs or fluorescent tube type T5, T8 or T12 lighting. IMO T5s have the best BANG for the BUCK. Most pygmy, spathulata and capensis sundews do well. I haven't grown any pings yet but I'm sure someone who has will chime in.

I grow butterworts but they are all "open tray", on a grow rack. what I do have in a terrarium setup are tropical sundews, a couple token Asian pitcher plants, and several bladderworts. Here are a few of the plants:

{{gwi:561150}}

{{gwi:561152}}

{{gwi:561154}}

{{gwi:561156}}

{{gwi:561158}}

{{gwi:561160}}

{{gwi:561162}}

{{gwi:561162}}

{{gwi:561164}}

{{gwi:561167}}

I didn't mention Nepenthes because the OP said smaller plants. Sure they can be small for the first year or 2 but when they start eating well look out.