There's no strain of coffee bean that has no caffeine when it is grown, but you can find whole-bean, decaffeinated coffee. "Decaffeinated" coffee has been treated to have most of the caffeine removed. Decaffeination is done when the beans are still whole, so you can certainly find whole-bean, decaffeinated coffee (though I suppose decaffeination could also be done after grinding). The decaffeination process is often done with whole, green (not-yet-roasted) beans, which are subsequently roasted (still whole). Most places will sell whole-bean, decaf coffee -- local coffee roasters, coffee shops, markets, mail order from the usual suspects... Starbucks, illy, Lavazza, Peets, ... Look for "whole bean decaf".
For more on the subject of decaf coffee, see this question about how decaf coffee beans are produced and another question about the fact that decaf coffee still has a little caffeine in it.
The concept of "half-caf" coffee has become popular, mixing part decaffeinated beans with part regular (not-decaffeinated) beans, which might be a good option in your case to reduce (but not eliminate) the caffeine. These half-and-half blends are also available from retailers.