[legomaniac89]

You (or more specifically, your Harlequins) would definitely be safer with Cherries, but its really a matter of opinion. Tigers are very entertaining to watch and get very nice color, but so do Cherries. It would be a lot of red in the tank with Harlequins and Cherries though...
There are like 10 million different types of Asian barbs and other fish you could try too, so don't limit yourself to just those few.