Try out
Dunlop Tortex H3's. They are purple picks with a slight powder coating on them which makes them very "grippy." They won't slip out of your fingers. The size and shape is absolutely perfect, in my opinion. I know what you are talking about by saying that the stubbys are too small and that the "regular" sizes picks are too big. I've tested a lot of them out. The best picks that I can find are the H3's.
They are the picks to the far right in this picture:
You can order a pack through their website.
www.jimdunlop.com