Ours came with A&E main awning and slide topper. The info is in your Sunline Owner's Booklet (binder) if you have it. There should also be a tag on the roller tube itself if you unroll the awning all the way. I have the binder and knew what to order, but when I replaced our slide topper awning last year I found one on the tube.
2003 280SR #8250
2004 Ford E-350 Wagon XLT, 6.8L V-10, 4.10
Equal-i-zer, Prodigy, McKesh
"RVing--Wherever We Go, We're Always At Home"