Really you shouldn't be thinking about if you think they look nice, it's if you can give them the conditions they need, and if you only have space for 2 then they won't feel at home.
Neal
PS - Yes I do know how hard it is to turn down a fish you really like, I had to do it before when I wanted a Black Ghost Knife and a Silver Shark for my 20 Gallon after seeing my brother with them in his 15, but when I done my research I was like, erm no can do! Shame my brother won't do anything about his though...