Well, Fultons is at the Marketplace shopping area, while Cirque is down at the West Side... So you'll have to cut through or bypass Pleasure Island one way or the other... If you want to park near Fultons, park near the McDonalds... otherwise, you could park waaaaaaaaay down by West Side and be close to Cirque, and just walk to Fultons for dinner.
There is also a ferry that you can take at certain hours between the two sides, but the last time we went we decided it wasn't worth waiting for the boat to get there... so we just walked the distance. You could do that, as well.
Up to you =)