I've had very good service from
http://www.aerialix.com. They provide kits for the guerrilla.net low-pwr omni design.
I bought a kit and found it very easy to assemble. The other cool thing for those DIY'ers out there that hobbled together a mount out of wood, cable ties and hoseclamps, is that the mount can be
used to mount thier omni-directional antennas or any you constructed that end with an N bulkhead connector.
They also have competitive prices for custom cables, and a pretty quick turn around time.
SilverF.