Easier to build your own and that way you can adapt it to your liking. For instance, I opted for a slightly better battery, a 12ah rather than the usual 7ah battery. I also opted for a 5.5 ltr per min pump and on a previous model I fitted a remote switch for on/off control.
By making a pump/controller box yourself, you can tailor it to your needs and have a better understanding of how it all works, allowing you to fix any hiccups that come along