I know questions like this get posted a lot on this website. This would be my first wedding cake and I really have no idea how much to charge. I will post the pictures of the wedding cake, and the groom's cake. She needs it to feed 200 people, is this enough cake or is it too much cake? Any help would be greatly appreciated! Also if the groom's cake is chocolate would it work to put white fondant on top of it?
Yes, you can put white fondant on a chocolate cake, although the picture you posted looks like buttercream to me (but I could be wrong, it's just kind of small and hard to see!).
Topsy-turvy cakes are difficult and should be priced accordingly. It's hard to say how much the cake in the picture serves without knowing the pan sizes. You should probably use Wilton's or Earlene's serving guide to figure out what pans you should use to achieve your 200 servings.
I'd personally price the topsy-turvy at $5 - $8 per serving, and around $3/serving for the groom's, if it's buttercream. I have an article here that you may want to read in regards to setting your pricing structure.