Ritteri and LTA aren't easy to keep.
If you want easy to keep 'nems, then it's BTA, RBTA, condylactis, and flower 'nems.
70W over a 14g might seem like a lot of light but it isn't. 70W lighting isn't really intense and I would take a look at 150W if you really want to keep 'nems in that size tank.