How can I model two inverters in one system?

If the PV array has a dedicated inverter, I would model that as an AC PV system.  (That's possible in the latest version 2.67 beta, but not in version 2.19.)  Just make sure that the costs that you enter in the PV cost table include the cost of that inverter, and when you indicate the power capacity of the PV array in the cost table and the sizes-to-consider table, you enter the capacity in AC kW.

You could do the same for the wind turbine, although since it will be alone on the DC bus you could model it as a DC turbine, add a converter to the schematic, and use that converter to model the wind turbine's inverter.