@ Michael NC,
Like Dawn .. Mentioned if your woodshop skilled you can save a FEW bucks making your Flow-box but for the price difference I wouldn't. I do build hive boxes but for my one Flow-hive I bought the whole kit (lock, stock, n barrel)..
For your second deep above the brood box can be acquired from Beethinking.com, Brushy Mtn or other local providers. I chose to use Beethinking.com as they built my Flow-components so all the 8 frame honey/brood boxes matched.
Get that order in as Flow is advertising local good supply n fast shipping. That way you can add Tung Oil or Exterior paint n have time for the finish to cure. Also as important ! Get your Bees (I'd only go with 5 frame Nuc). It gives you a much better running start.
here's a pix of my Flow-hive plus. This is a special setup with double moisture absorbent boxed above the normal double deep box system.
I have also added a hive monitoring system so I can monitor my hives temps, humidity n weigh during the winter month. I only have one monitor on in my apiary of five hives. I'm part of a local college research group of bees. They are pricy so doubt that's going to be priority for you this first year at all but handy. Also find a local bee club n attend some classes. I'd strong suggest a mentor as well. That's really got me out of some scrapes several times.
Good luck n get going bro,