To be honest I'm not a big fan of any of the pairs together. I don't too much mind twins with names that begin with the same letter, but it does turn me off a bit. I suppose I'd pick Hudson Allen and Heath James and Sophia Grace and Sadie Faith. If I could mix and match though, my favorite pairs would be Connor James and Heath Allen and Abigail Hope and Sadie Grace.
I don't suppose we get to know what your twins are actually named? :) I like this idea though... makes me want to post about the names we were considering for our kids but didn't end up using!