I figured out how to get back the md5 checksum option in disk utility.
defaults write com.apple.DiskUtility advanced-image-options 1
I checked the md5 checksum of the iso in terminal and I get a different answer than I do in disk utility, weird. The hash in terminal is correct, the one listed in disk utility is wrong. What is up with that?
Edit: Nevermind, I was selecting "MD5 image checksum" instead of "MD5" in disk utility. Evidently they are different.