Dan,
It's tough when you want something specific. Maybe you can be more flexible and maybe purchase a stronger unit or one a little less powerful used. Otherwise, paying for a new unit can be expensive.
PS. Make sure to get an in-line unit rather than a drop in. Drop in units are more expensive to operate and are awkward to use. I tried a drop in unit, and quickly saw how this style is not for me.
PSS. I have a 1/3 unit on my 55 gallong and I love it. I needed to be able to compensate for a very hot office and it works great. You will also need a temperature controller, so make sure you either have it included or be ready to buy that also. You will need it.
PSSS. I recommend a dual stage controller. The controller is much more accurate than just using my heaters. The controller is very accurate and I only deviate by 2 degrees per heat or 4 degrees for both extremes of hot and cold. The idea, is that heaters are designed to turn on frequently and chillers are recommended to vary by 2 degrees so they don't go on as frequent.
Hope this info is useful.
BTW, chillers are very expensive to operate.
