Hi,
The Xantrex is not a true hybrid inverter. It will not blend power from shore power and battery bank, nor from generator and battery bank. It is a single phase power device so not well suited to a 50 amp service in an RV.
For true hybrid operation look at Magnum, Outback, or Victron. They offer 12, 24 and 48 volt units.
Best price on the Magnum 3012 is Imarine. Magnum has 24 and 48 volt models as well.
SMK's approach has a lot of merit. Separate components are often more flexible. The only item missing is the load support feature of the true hybrid inverter/chargers, so if you don't need that then the separate components are simpler and inherently more reliable, not to mention a heck of a lot cheaper.