While it's good economic sense to use budget panniers for limited usage, I don't suggest scrimping too much when it comes to the rack(s). I like Old Man Mountain racks, but have not tried any of the other previous suggestions. My back-up touring bike is a high mileage example I use primarily as a beater bike. It has a Blackburn rear rack, that while not very expensive, has withstood quite a bit of usage.

Using front and rear racks and four panniers will allow less stress on the cargo system and allow for balancing the load. Just because one can load everything in the more common rear rack with pannier doesn't make it the best option, in particular when approaching the 40 lb. mark.

Brad