Crystal tetra and red pencilfish

[Mazan]

I’ve been looking around for suitable small shoaling species for the mid/upper tank levels, and recently I have seen these offered for sale that look interesting: Crystal or pi tetra, (Protocheirodon pi) and red pencilfish (Nannostomus mortenthaleri). I was wondering if any of you might have experience with these as tank mates for apistogramma. I can find very little info on the crystal tetra, other than peaceful and hardy, but a lot of info on different tetras also say that, then I read that they are bad fin nippers ( like the blue tetra for example that also looks nice, is available and I was considering, but it is one of the bad ones apparently.). Regarding the pencilfish, I like this a lot, but it sounds like they could be a bit difficult to keep? The same seller also has black emperor tetras, but I am not that keen on the black variety, prefer the normal ones. Also I was thinking of possibly getting a few very small (at the moment) angelfish and wonder if as they grow they might eat these smaller fish, though I have seen many times angels kept with neons. If any of you have any experience with these species please let me know. My tank is 120cm x 40 x 50, could I keep both of these species and how many of each would be best? I could also get hatchetfish but the other two appeal more. I have not got any other fish in the tank yet by the way, still at the planning stage and still deciding which Apistogramma to get....