actually i used a fujica MA-1 (entire thing is made of plastic except for the lens which is glass, i think). i modified it so that it has a 49mm thread on the lens and attached one of those grobatig wide angle lens attachements.
i don't think there are wide angle toy cameras around. so i guess you'll just have to make one.
it's pretty easy, just epoxy/thread/weld/tape a suitable filter onto the front of your lens (buy the filters cheap from cash converters condition of the glass or colour doesn't matter cause your interested only with the ring.) in this case i used a 49mm filter thread so i can attach any 49mm filter or use step up/down adaptors to screw on any wide/tele lens attachments.
do note that these cameras don't have through-the-lens viewing (they're dirt cheap for goodness sakes!) so you'll just have to experiment and estimate what will be included in your picture. it's a lotta fun though!