@mj26 I have had no trouble with ALA on my stomach. Every once in a while I will get some pretty good heartburn (other folks have mentioned this as well), but it doesn't last more than a few minutes. Sometimes I will take two Rolaids if I have them handy and that takes care of it. I'm not sure if the heartburn is a result of what I take it with (I do always take it with food), as it hasn't happened enough for me to be bothered with.
Personally, I have not taken acetyl-L-carnitine. I just looked that up and I shouldn't think that you would need both, although perhaps one might work better for you than the other. Whatever you try, unless it clearly makes you worse, do try for 3 months before deciding if it makes a positive difference or not.