One of my "other" hobbies is electronics, and as a die-hard DIY went to the web to look at some passive crossover schematics.
I modeled a couple with Tina Pro
http://www.tina.com/ but all that I modeled rolled WAY past 80HZ, some even into the 2Khz range. I toyed with various values with little luck getting even a semi-sharp rolloff. I'm not sure if it's problems with the programs calculations, or if passive filters are just that way.
Given that, I did decide to go with a powered front end LP crossover which should be fairly easy to build. If it all works out I'd put it in a nice case to finish it off.
If the design doesn't test satisfactory I'll probably go with the Behringer
Thanks again for the help.