I'll need a cutting list for quoting . . . .
Box section (I'd say) is preferrable . . . Straight cut (as opposed to mitre-cut) ends is best, but not 100% essential.
I'd typically go for the lightest section (eg. 3.2mm wall) but would go for whatever works out easiest for my supplier . . . . assuming he's O.K to do it.
It must be a complete list when it is done because I don't want any additions at the end.