The size isn't as much of a giveaway as the MD5sums - if they are the same, then it's very likely they are the exact same file. Looks like the MD5s are the same for both of those. My only guess is the regular SuSE iso comes with 64-bit support, or at the very least comes with a 64-bit kernel in addition to the normal one. I'm guessing you are safe in downloading either one of them, and you will still be able to get 64-bit support.
But then, I'm doing a lot of guessing
Maybe someone with more knowledge of SuSE would know for sure.