You won't get that wah tone Slash got. Even he has remarked that he'll never get that tone again. There was a really great issue of Guitar World 10 years after "Appetite" was released that spilled all the studio tricks. Slash's producer had to lease a couple of old Marshalls that were Jubilee's. They went back to the store after the recording was through. And the wah was an OLD Crybaby with an original Fasel inductor. Even though Dunlop has brought them back with the Crybaby classic & 535Q, etc., I'm sure the Fasel on Slash's wah was wound differently.
I would recommend the Crybaby Classic. Slash's new wah would be cool too.