I wanted to get some time with the Miller before commenting again, but as Steve already said above, I messaged him within just a few days of receiving the kit and told him I really appreciated the suggestion. The Miller is a great buy and quite honestly, does everything exactly how I want it to. Great product and it's a solid, sturdy rig.
I am using the setup in two configurations, one with a decked out RED One attached (handles, original EVF, 5" screen, v-lock batteries, lots of connections, Teradek wireless, rails, 18-85 RP Zoom plus bracket and handle, RP matte box, etc. The Miller handles it just beautifully. I bought the Miller offset quick plate for this purpose.
The second setup is with an Epic (currently rented, but our own will be here shortly). We're using the Epic, the quick lock, a dovetail plate, 5" touch, and a gaping hole where our side handle and REDmote are waiting to be placed (please come quick!). Even with the 300mm attached, the combination is just superb. Does everything wonderfully. Also cleans up nice after a trek into the dusty, dirty, SW desert.
Finally, for mobile work, we're keeping the One in the studio and carrying only the Epic for now. For that combination, we're using the Gitzo Monopod 5561T and going very light-weight. Great combination for our purposes. Couldn't be happier. We have the E Mantis shoulder system to use, but have not had the need just yet.
Going to buy the Miller locking wheels dolly system to add to the tripod soon. I really enjoy that setup.
Thanks again everyone for their recommendations. Very helpful.
**UPDATE: Unfortunately see next post below.