i dont think there are many strikers out there who could directly replace trezeguet. trezeguet is a goal scoring machine, but toni has shown he is that also. and mentioned already in these forums, toni probably has more to offer than just goals.
Besides Klose and maybe Huntelaar, two very good strikers in my opinion, there are not any more out there.
Toni is probably the safest option, with klose needing time to adapt and of course huntelaar would have a lot to prove being his age moving to a tougher league.