Hi David,
If you want to get started now, you can purchase a Flow Hive Classic as you mentioned, or you can buy a brood box(8 standard frames to match 6 Flow Frames), roof and bottom board.
The brood box will match up with the Flow Hive 2, there is just a couple of millimetres difference, hardly visible.
This will allow you to have your brood box going, and you can either use this as a second brood box later or have it as a spare later for splits and swarms.
You can buy the equipment from any supplier in Langstroth 8 size if you would like to match the Flow Hive 2, or you can email customer support to order a matching brood box, bottom board and roof(when in stock). Just include your order number or the email address you used when you ordered).
https://www.honeyflow.com/contact/p/3
