What's my best choice for a Fantina team?

I'm guaranteed to find a Ralts on R208 (dupes clause), but I'm not guaranteed to catch it. I was thinking of dropping Togepi (Hustle ability and Timid nature), and adding in Cleffa for Sing (so I have a better chance at catching pokemon), and trading out Rotom for Gastly for training, then trade Monferno for Rotom just before the fight