Layout Based On A Pick List?

Layout Based On A Pick List?

I am trying to use this to manage multiple client types.

One of the client types is "Buyer" the other is "Seller"

When I enter a new lead, I want to be able to select Buyer or Seller from a pick list, and based on that, display the corresponding layout.

I also need to change the stages based on that pick-list as well.

Can somebody point me in the right direction?