Hi Onward - you may want to look at
buhnerhealinglyme.com/ if you haven't already - there's a lot of Q&A there and many of your questions are answered there.
I found it a little challenging to get the bulk herbs down in any way besides the dreaded capsules, so I buy the empties and make my own, though sometimes I'll mix the powder in with juice or a smoothie. Personally, I think I prefer the raintree cat's claw, though I do use the MRH brand and haven't necessarily had adverse effects - it's always hard to tell exactly what's working when you take so many things, but I think it should do just fine too - they're a really solid brand from what I can tell.
Just with the eleuthero - I believe Buhner prefers it in tincture form. I'm far from an herbalist so I can't tell you why or if the powder would be equally effective - though my guess is it would still be beneficial.
Hope this helps some, and, again, I know the dosages are listed somewhere on that website for the bulk herbs, something like a tbsp per dose (4x/day, which you need to build up to) or something along those lines.