Do a search for "saddle bag" and "saddlebag".... be sure to change the drop-down from the default "week" to something longer. You'll find lots of pictures/brands/descriptions. Might find something you like.
Mine are Saddlemen Large Drifters. I modified the buckle (posted a thread you can search for if you want) to make it a quick-release latch, much easier! I bought them from DennisKirk.com although if I had to do over again, I think I'd go with the Medium, and probably slant too. Saddlemen recommended the Large, but I think they are a bit big. But they do carry alot! My leather jacket, chaps, couple sweatshirts, plenty of grocery room. I think they measure about 15 x 10-1/2 x 5-3/4.
I also made a hard-mount bracket which I also detailed in another thread.
Here's how they look on the bike: