I want to try a very similar setup, and probably will on my medium scale Persuader 5 if I ever get around to it. I also found it to difficult to get good notes below the low D, and also found almost no need for them. I was going to go Bb on the top string though, just to maintain simplicity in fingering bass patterns. I guess that since I chord very infrequently, that benefit of the A on top is less important to me.
I figured that, worst case, I could use a capo if I ever needed to cover a tune that relies on the traditional open strings.
-Bob