I made the same decision for the Zephyr
I started with a 4X 8 HF Trailer. I wanted more room inside so I built a wooden frame to support the TD floor and mounted the frame to the trailer with stainless carriage bolts. It is 67" wide OD
My Build Journal is found at
http://www.nfdc.net/home/cbdb/Micro%20Camper.htm
Here is the under side of the frame
This is the way the framed deck looked as I started the build
You can do it too!
DEE
Grace happens...