Also remember not to use an old lead based paint so when you and your family are eating paint chips(yum yum), your kids won't get lead poisoning. A painted countertop would be no different that tearing off a piece of painted house siding(would you prepare food off of that).
Measure your countertops and go to your local home cheapo and find a new one. They may even have a list of installers. They start at less than $10 a running foot for a butcher block one. I've seen stuff for $5 a foot and sometimes there are some odd left over lengths they sell fairly cheap. They are only held down by a few screws.
But in the end, it is your countertop, your family, and your nickle. As long as you aren't serving food to the public, then do what you want. Go to your local sherwin-williams/paint store and see what they would recommend and guarantee. Check to see if your health department and the epa allows food preparation off of painted surfaces at restaurants and I'd bet they don't.