I'm here in the Northeast too, and have been using Kifaru packs since 2014. If I were to buy only one, it would be the Duplex Lite Frame and a big bag. Something like a Hoodlum. Or, find a used bag to save some coin off of the FB group or Rokslide. I've used that setup to hang-and-hunt with my saddle gear late season when I want to carry my Sitka Bibs and Fanatic jacket. I've carried a 150# ladder stand with that frame - albeit not more than about 500 yards.
The sherman pocket isn't a real bag like the 22 Mag, more of a pocket like the name. Shape Charge has its' own frame but can be attached to the frames. 357 Mag has its' own frame, but don't think you can use it with the external frame. 22 Mag is just a bag, and can only be used with the frame.
Clear as mud, right?
I tried the Stryker XL, sold it. I prefer the 22 Mag but I 'm running two frames / two bags (22 Mag, Hoodlum). I'm selling some extra gear now, and will be picking up a shape charge for lighter weight stuff.