Personally I prefer to build my own sump out of a glass tank. If you're handy and don't mind saving a few $$, for your 125 a standard 55 would make a great, spacious sump/fuge. You know what equipment and the amount of space they need so you could place the baffles where they make sense as opposed to paying tons of $$ for an off the shelf sump that is not customized for your equipment. Just my 2 cents from experience with my first off the shelf sump, I ditched it after just a few months....8 years ago.