My criteria for the choice of purse were as follows;
plain black - the colours should be from the buttons, white may work as well,
simple style - too many dangling bits, exterior buckles and exterior pockets make it difficult to attach the buttons and also take away the focus from the buttons,
smooth material - this makes it easier to glue the buttons to, fuzzy or course materials would be harder, and
cost effective - the less expensive the better.
After a few hours of searching on eBay, I picked up a
Dyeables handbag style 1807 dyed black for $7 plus $12 shipping to Australia. The handbag is a very basic style with lots of large flat surfaces; the clasp is hidden out of the way as well.