I built a Versa Tube 30X30 shade cover in 2002, then added a Versa tube 10' wide lean to a few years later making it 40' wide. Last week I extended the length, it is now 47X40. Versa Tube has been great to work with, their engineers are accessable for questions etc. and they are easy to erect, I get 2 buddies to help and we git'er done in one day using a scissorlift. The sides are enclosed and the ends are open.
I buy the metal sheeting separately from MBCI. We were amazed that the original sheeting matched the new so well, virtually no fading. We are fortunate to have a manufacturing plant from both companies nearby.