I usually use bone, Wegen 2.5mm and horn (when amplified) picks.
Yesterday I went to a local music emporium and purchased a small selection of picks from Timber Tone. I got their Stone Tone (Jade) and Buffalo Bone picks. They have a great shape and are a bit bigger than a Dunlop Gator, I think they are about 2.25mm-2.5mm. They are also competitively priced. Another great alternative.
Here is their web site. http://www.timber-tones.com/