Metal Mart will likely have what you need, but they are more expensive. They are over on Dequindre, 2 doors north of 13 mile on the east side. I've bought a lot of drops from them, as well as some full lengths. They have cut fees too, so make sure you are saving $$ by getting a cut length over buying the whole length.
Pontiac Steel is a good shop to deal with too. They have even more drops, so you might find 6' on the rack. Prices historically have been pretty good there too, but steel keeps going up in price lately. They used to be open on Saturday, but I think they are now open late on Wed instead. Worth a call to doublecheck.
Factory steel I deal with only as a last resort. They are always to most expensive, but open on Sunday. It's a predominantly Jewish run place, so they are closed on Saturday (Jewish Sabbath). If you absolutley need a hunk of steel on Sunday though, that's the place.
Do your homework, I have often found that buying a full length is about the same or only slightly more than paying for the cut piece after all of the cut fees are figured in.
I have a bunch of steel laying around, but nothing in 3x2 sorry.
