Kyuujoushow Limited Edition (A):
The LE-A version has a Music Clip made just for this, a first for Kanjani8! A fictional TV Show directed by a mysterious director!!
Kyuujoushow Limited Edition (B):
The LE-B version has a Music Clip for Hitotsu no Uta, which starts with introduction footage of the members deciding on the song title + footage from the DVD release events that took place at Kyosera Dome Osaka, Tokyo, and Nagoya.
Erm, I don't know if this info in any way could help you to decide which version to buy, so I guess, both? LOL. And the Regular Version has 4+4 songs which is awesome, considering that last time, Musekinin Hero's RE only has 2+1 songs. :)