I built peaked dog kennel roofs out of chainlink toprails and already-formed 3-way and 4-way connectors (not sure what benders are) -- got those at an online greenhouse store, don't remember which one. Think of those car canopies in a box -- but upgraded -- a lot.
My big kennel roof is 10'x60' and is one long section, 6' in the air with dog kennels underneath. So in gardening terms, think a peaked screenhouse with no sides or ends.
I used bulk greenhouse mesh instead of tarps because the wind here slices solid tarps like a knife through butter, I learned that lesson after buying the second tarp. My 2006 greenhouse mesh has lasted through snows, winds, dogs, etc.
The trick for mine was to cut off the 4" narrow part from the toprail and toss it because connectors don't fit. And the sections were still 10' long after.
One STRONG suggestion, if you buy the connectors, use the chainlink toprails for everything EXCEPT the peak ridgeline. Take the connectors to a pipe store and buy pipe that fits OUTSIDE the connector, instead of inside like the toprails. OUTSIDE the connector sizes are immensely stronger than toprail and if the ridgeline fails, everything else fails. If the ridgeline holds, everything else holds... even with a tree across the ridgeline.
I am in the process of building a 20X 30 hoop house using 13/8 toprail. I bought a bender on Ebay ( 129.95 + shipping) . It is easy to use and fast too. The 6ft. line post are cut in half and driven into the ground to hold the hoops. I have the posts in the ground with treated 2X12s bolted to them to make the whole thing stronger and to attach the cover .