Two useful tips:

When I first ordered a Bagman support, my DH convinced me to get the SMALLER one, the Sport, rather than the larger "Expedition" bagman.
I was really glad he did, because the larger one woud have been way overkill even for my relatively large Little Joe bag.

Most of these great bags still benefit from a stiffener of some kind inside the bottom so they don't sag in strange ways. I use the flat plastic lid from a cheapo rectangular storage tub and cut a piece to fit the bottom of my bags. They are stiff and very lightweight and don't crack or wear out like cardboard.
Each lid can usually make 2 or 3 bag stiffeners.