[wingnut60]

Yes, you can have the gen connected to the cord, but they only have a 30amp plugin. You have to have the correct plug and wired correctly for 50amp, assuming the gen puts out 50amps. You can always use your 50amp cord with a 30 amp adapter to the gens with the 30amp plug.

As to the 2x6volts--it is your choice, but it is hard to find true deep cycle 12volts--most of them are made for cranking and momentary use. The 6volts will outlast the 12s.
Do it either way, most opt for 6volts after using 2x12volts. If you are going to be plugged in most of the time, 2x12 will work; if you will be doing a lot of dry-camping, you will soon find that the 2x6volts work better/last longer.