We have painted countertops twice.  I think we just used regular old latex paint.  First one lasted 8 years before we moved and was to the point of needing redone.  Second one didn't go as well, we replaced with laminate tops(which aren't too bad).  I'd go for it if you are on a budget.  Worst case you are out 20 bucks and some time.  Clean with TSP, prime and paint a couple coats.  Ben