If you are talking buying roasted beans, suggest purchasing a Swiss Water Process Decaff coffee.
They decaff a number of diff varieties of coffee but owing to lower turnover of decaff in general, it would be hard to find a roaster from which you can buy a selection to try...most roasters pick a decaff they like and stick with just one variety.
My company has tried a few, and I quite like their guatemala, sumatra, and a thing they call "espresso blend". When we finish the one were using at the moment ( a colombian), well go back to the espresso blend SWP decaff.
Incidentally, the Swiss Water Process company is in Canada, not Switzerland!