looking to buy an auto topoff

[Chipie]

Oh believe me, i'm looking pretty much everywhere. I have an auto top off from autotopoff.com in my 65 gallon's sump and it works very well, but this one i need for a 18 gallons tank without sump. So i'm trying to find something on the smaller side so it doesn't look too bad in it.
Wish me luck. Thanks