I have a similar situation, in rural Tasmania, although not quite as spread out. I plan to buy one iotawatt now for the meter box and get another for the house later rather than spend all that money at once. I have different reasons for needing it than you do though.
From my reading of the docs we don’t need a neutral CT; certainly I don’t have one for my zappi EV charger which uses monitoring to direct excess solar into the car.
I’ll need 8x100A at the meter box (grid input, house output, and two for other circuits at the box). Ideally one would be 50A but the $5 difference isn’t worth worrying about. Future plans may involve another 3 so the iotawatt seems perfect for this.
Once I start monitoring the house I will easily fill all 14 inputs of a second iotawatt, but I’d prefer to save $5 per CT and use 50A. Sadly I doubt there’s any way to do that while costing less than the savings.
[update: I asked them and they now only sell 100A.]