Greetings and salutations!
Are those my only two choices to pick from?
Both are equally interesting, but one has some nice coloring to it and one is mostly yellow green. One is fast growing and the other is slow. One will eventually look like another interestingly strange looking species (Whisper aloud N. lowii) but not so same.
if I were you, I'd try a hybrid perhaps since they are slightly faster growers and you won't give up cp's if you decide to get bored while awaiting your next leaf from your new plant.
N. eymae x veitchii is interesting, while lowers resemble a mottled N. veitchii (with stripes) the uppers resemble a large N. inermis.
N. lowii x ventricosa (if you can find it) rivals the sought-after N. Trusmardiensis any day and grows ten times faster. I think the pitchers looks more attractive and the pitchers are as hard as wood too!
N. ventricosa x ___ you fill in the blank. Anything crossed with N. ventricosa is a good easy grower and whatever it is crossed to, the pitchers resemble them a lot (i.e. N. ventricosa x sibuyanensis, pitchers are wide and large like a N. sibuyanensis, N. ventricosa x truncata, pitchers are like N. truncata in shape, but may be colored like a ventricosa, etc.)
Good luck!
Michael