To be honest I didn't find the racks too hard, but I went with a relatively simple design. The trickiest part was making the front rack rectangle meet back up in the right place.
I bought one of those $20ish tube benders off ebay, which felt like it was on the verge of breaking every bend, but it held out, and made half decent bends. I reckon you could get away without a bender if you don't mind the tube flattening out a bit more. Just bend it around something round.