I have a HandSpring Visor Deluxe, which fits what you're describing. However, the Visors are being phased out by Handspring to be replaced with the Treo series. Some are still available for $99 here: http://www.handspring.com/products/outlet/refurb_deluxe.jhtml

As far as what's available now, the Palm m130 may fit your needs:

http://www.palm.com/products/palmm130/