Have you thought about a Legless Lizard? They stay small and eat insects, small mice, hardboiled eggs, and will readily take moist dog/cat food as well. They do fine without rodents in their diet, but they will take them.
I couldn't agree more with what Marisa said. Just because a snake is simpler than another species to keep doesn't make that snake any better or worse. I personally don't like ribbons just because they don't appeal to me, same goes for most colubrids, and burms certainly don't. I have worked with lots of burms and I just don't care for the way they look and act, and I do not find them to be a challenge to keep. Doesn't mean that these snakes are inferior to the ones I do like. Its all a matter of preference.
I wish anyone luck in getting either of these to eat fish or insects