For some reason I throught Transfer Express had Pennants. I had a catalog from another company but I threw it away months ago since I didn't use it.
I just saw a thread for the ISS show in Fort Worth. If you go you might find a supplier. Even if you don't, sign up and you'll get a hundred emails from all the suppliers. Hopefully one has Pennants.
That's a tough way to find them, but at least you know they're in the industry. Also, Printwear Magazine has a section in the back with suppliers. Maybe someone ran an ad.