@Bhatch the load lifter angle matters most when you have heavy weights, be that packing in a full camp or better yet packing out meat. I have a similarly long torso length, so as
@Kenneth@Kifaru notes definitely get the 26" or you have automatically handcuffed yourself for those times when you do have heavy weight. It may be tempting to get the 24" as it will work...right up until you have heavy loads.
While a 24" would work, you will have lost the ability to transfer the load properly to your pelvis. Or perhaps better stated not able to transfer the load in a more ideal way based on your anatomy. The higher frame is not necessary for day hunting or lighter load scenarios and make you slightly more nimble in heavy cover, but in my opinion it will hamper you during a load/pack out.
The load lifters themselves won't be in the way in brush/cover, as the frame and bag (and any peripherals, like lids or pouches) will be above the load lifter, even in its highest position. It's about the height of the frame itself.
The Kifaru frames have 3 positions for the load lifters from the shoulder straps to the bag (or frame, if you ever wear a frame without back for meat/meat quarters, or bulky items). With a light load or while in day mode you can lower them to get the straps out of your peripheral vision. The load lifter function itself will draw the frame in toward your back and allow the shoulder straps to "lift" off your shoulders. Don't go crazy there, just cinch them up a little bit to raise the straps off your shoulders a touch. This will affect the geometry of the whole system and you'll feel it settle the load down onto your pelvis, provided you have your belt positioned correctly.
Depending on what you go with—again based on your torso 26" is really the best for you if you plan on ever carrying heavier loads—you won't notice any of this until you have weight in the pack. It will be awkward with bare frame/empty pack. When you get weight it will settle down on your body pretty noticeably, so during setup be sure you load that bag up with something.
I'm an eastern and western hunter, so elected for the 26" knowing I want optimal performance in the worst-case scenario...which is actually the best case scenario because it means I'm packing out heavy elk meat. The 26" could be considered overkill in many ways on the east side, but it sounds right-sized for your body. The load lifters will function as load stabilizers with a smaller frame for your anatomy, meaning it will keep the frame closer to your back, which will still help and be more comfortable than the frame pulling away from your body. You'd likely get some "lift" with a 24," but again perhaps less than ideal based on your torso.
Both when loaded heavy and loaded light like in day mode, I'm constantly adjusting shoulder straps, load lifters, and sternum strap just to mix up where the load is affecting my body. This helps prevent over-stressing any particular part of your body throughout the day and helps increase stamina across a long day. Conditions will dictate this, too, like if crawling up steep slopes or in scree/boulder fields where you may want a little more freedom of movement.
I debated the Duplex Light vs. Tactical for some time since I'm a bit of an overkill guy and like the heaviest duty...everything. But, I elected for the Duplex Light vs. Tactical. Having a number of elk seasons and backpacking trips on my back with the Duplex Light I've not yet had a scenario where I wish I would have opted for the Tactical frame.
If you've not had a Kifaru frame before, you will be shocked and pleased how it handles heavy loads. I realized I'd been beating myself up for longer than I'm willing to admit before I transitioned to the Duplex platform.
