It depends on what your goals are. Typically you will want to have the holding company in an offshore jurisdiction where you don't have to worry about accounting and fiscal reporting, Seychelles is such a offshore jurisdiction, furthe for the trading company it depends what your target customer group is and where they are located (country).
In the last few months we have seen huge trends where a Seychelles company is acting as Holding for an Cyprus trading company, but it dosen't need to be so.
In regards to offshore banking, you will want to look into countries like Switzerland, Seychelles and even Cyprus.