Sorry for being late to the party!
Neps do great with veileds BUT they probably wont survive down in the sub as they need extremely high light. You can see one in the pic in the upper right and one vining across the middle. Honestly I doubt they are going to catch a lot of bugs, but they come in handy when you have a dead bug to get rid of! I have a few down midway, you have to experiment as they have varying light requirements.
The real ace is butterworts for catching the florid flies and gnats. Also needing a lot of light (up high, but not getting dried or baked) but they will attract the bugs from anywhere in the cage. Not sure if they are veiled safe as they are not on the list, but I had one with my veiled and got very annoyed as he immediately ate the flowers. So this one in with my k boehmei is very happy and doing its job.
Assuming you have a 48" cage I don't think there is any CP that will do well unless you have extremely powerful lights-even a Jungle Dawn is not enough for that distance.
VFT and American Pitcher Plants are a no-go unless you are willing to take them outside for the winter for dormancy.