I bought a 125 a few years ago and wished shortly thereafter that I went with either a 180 or 220.. Once you get it in your house, you feel that the width could be bigger.
x2 with my 120 that WILL need to be replaced in a few months
I'd go with a slower growing arowana such as a jardini and a bottom dweller such as a ray or catfish. But only since you did mention upgrading