Unless you have really soft, low pH water go with the lenticulata. The sp. 'atabapo II' are annoyingly prone to getting HITH since they come from pristine, black waters. So unless you have low pH, super soft, and extremely clean water, the atabapos are going to get HITH, you can count on it.
Plus lenticulata are generally more showy and colorful in comparison. Both are great fish though, I currently have both in my 300gal and love them all!