Spelling Workout is what I am going to use too, but Spelling Power may be just want your ds needs. There are more than a few moms who use that with their kids who don't like to spell (or just don't like spelling). Check it out. If you like it, why not start a thread on just that one curriculum and see what other moms say. (It is mentioned once in The Well Trained Mind if that matters to you.)
Jennifer