Damn, I was going to tell you to buy the Nashbar Commuter Rack but I can't find it anymore on their website. It was nearly square in back and had a HELL of an extension on the front and bottom for sizing. I've also got 13's and my "cargo bike" is a compact frame mtb which just makes the problem worse. The nashbar rack had a set of extendable struts on the bottom that were nearly twice the length on their other racks. I really like the design of the delta tho having seen one a while back. If I had to do it again I'd probably go with one of those.
As for panniers I don't have any real recommendations other than check how stiff the plastic inserts are. I had a pair from REI with inserts that got fairly floppy on hot days (not normally a problem in anchorage). Well last summer it got above 80 degrees and my panniers got so floppy that they wrapped around the bottom of the rack on a bump and got sucked into the rear wheel. I'd personally pick up a pair from a LBS. They'll probably let you try them out to see how they fit on your bike, you can check how easy it is to change their mounting position and I seriously doubt the price is going to be significantly different when you factor in shipping and getting a perfect fit the first time.