There all pretty easy to start off with if the right conditions are provided. Plenty of light, and stable water parameters, and low - med flow. They all demand excellent water quality. The deciding factor is in the lighting, most require high light with one exception being the Gigas, but this guy gets soo big that keeping it in an average aquarium would be a poor decision. You may be able to get away with lower lighting in some of the others, but its tough to tell when its not enough. Clams can slowly die without enough light and the warning signs are tough to detect until its too late.
Your lighting should be plenty for even the most light demanding clam provided the tank isnt more height than width/length. Even then I believe you'd be okay with a higher placement..