I recommend ASUS motherboards.
If you are looking for a cheap Slot-A MB, ASUS made some great boards and you can find them on eBay, new and used. The K7V is one such example:
http://search.ebay.com/search/search...query=ASUS+K7V
These are good (older) boards for the money and you can't lose with AMD Slot A processors for cost, peed and reliability. However, the ASUS K7V uses low density memory and will not work with high density memory. This memory is getting harder and harder to find. So a more ASUS modern board would be my suggestion.
www.asus.com
Of course, there are lots of other great boards... however, my personal perference is to use ASUS.
Here is a link to Slot A processors on eBay:
http://search.ebay.com/search/search...t&BasicSearch=