Matt, Be careful of the brown ones. If they have been dead for a while, fungi has already set in. When I collect cane I bundle them up and let them dry for a few weeks to a month, at least. You can be hand straightening them during this time too. Just un-bundle, straighten, re-bundle and set aside for a few more days and do again, etc. Pretty soon they should be relatively straight and only a little heat straightening will finish them off. I like to get the entire cane hot(tempering) and cool down slowly to ensure and maintain straightness.
My cane arrows are 29" for my 26" draw. I prefer long arrows anyway but especially with cane. You get more weight and better flight, at least I do. The natural taper of the cane and the resilience of it makes it less sensitive to spine issues.
Be sure the canes you harvested are mature. Most have a 3 year life cycle. The first year the shoot grows to its ultimate height. The second it matures(walls thicken and paper like node sheaths begins to deteriorate) and after the 3rd year they turn brown and die. Ideally you want cane after the second growing season(now) and into the 3rd before it dies.
I'm off to my hunt club in GA for the weekend. See ya'll Sunday evening. Pat