No, The Zephyr is not for "G".
You need a 8 amp command station, DCS200 - $246.00
A throttle, UT4 - $64.00
A decoder, A MRC 8 amp G decoder is on sale for $11.00 at St Aubins
A full featured Sound card. SFX064 $56.00 Steam or Diesel.
$377.00 is a stiff up front cost.
But, what happens when you have 10 locos?
What happens when you want to run 4 or five at a time?
Set up a spread sheet tp compare DC and DCC. For a DC block system add up every foot of wire, every toggle switch, every screw terminal, every insulated joiner, every battery you need for sound and lights to work, every single part you need for the layout you expect to have.
Do the Same for DCC.
You will find that to run multiple trains, at some point, DCC will have a cost advantage over DC. For most people the breaking point is THREE or FOUR locos. Then consider that all your lighted cars are constant, full time lighting. Sound cards work even when sitting idle all day. You have control over every light and sound. Locos run smoother and don't stall a slow speeds, etc. The coice is even more compelling.
You can get most of those benefits without DCC. Easy, buy only imported brass locos, add lots of little batteries and electronics, buy $200.00 sound cards (they still don't give you all the features and control of the SFX064). Then where is thhe cost advantage of DC?
I realize it is easy to pay 4 or 5 dollars for a toggle switch, or 20 dollars for a roll of wire. I's hard to shell out $300 for a system all at once and tempting to buy another loco instead. The question is. "How much more will you spend over the next year or so if you stick with DC?"