I have found german rye bread to work quite well with the old BG levels. Most bread makes my BG levels go quite high (even wholewheat pitta) but not so much with rye bread - there are a lot of different types available too (pumperknickel, multi-grain, plain rye) and they are quite nice toasted with cheese.
I'll have to look out for the Burgen Bread and give it a try.