Regarding the wire basket, just be careful to check if it will have heel clearance.
I've sometimes placed a briefcase sideways on my rear rack (handle towards the seat post) and run a bungee cord from one back corner of the rack over the briefcase, under the front of the rack and then back over the briefcase again to the other back corner of the rack. That would be for a softer brief case so the bungee presses into it, and one where you don't care about scuffing. You can run the cord through the briefcase handle for a little extra security.
Last edited by cooker; 04-08-13 at 03:23 PM.