First, what is your meta? Just like what Ghost said, GeChamp gets SP's. Mother Gengar is more for those power users and spread (like any Gengar deck) but with more use of Nidoqueen. So, we need to know the meta first.
Ok, thanks. I think I'll just stick with Mother Gengar. SP is not very popular in may area (I guess, seeing the Senior/Junior's decks in CC). However, many rely purely on Poke-Bodies and Poke-Powers, so I could abuse that.
I think you should play SPs to counter your meta Dialga G X with SPs. Dialga locks bodies and power spray the powers. Just a suggestion but from the two you said I would pick mother gengar.