Tony has two sizes, both for a low, low price that will spin your head *(What do you expect for such a cool plant)...
...and one's got my name on it.
N. diatas is, in my experience to date, NOT a small plant. *It's easily the biggest plant in my highland terrarium, and the leaves have doubled in length over the last three months or so. Incidentally, that one came from Tony, too.
Adnata is nice and small, but probably doesn't like that much cold. *My singalana has been very small for quite a while, so it might be a good option for a year or two. *Of course, lowii grows slowly, so that's good for a few years. *Same for villosa (Schloaty, how can you EVER forget villosa).