Adrian
Moka Kadir has no brazilian beans in it. It consists of ethiopian and yemeni coffees (a red sea blend). I like it a lot and try to always keep some around for a nice change of pace week.
As for your suggestion to buy 20# of blend #7 and be done with it - I did buy 10# immediately after reading about dextral strike and I still have 6# left.

I've experimented to where I've found a nice cup from it but it was real work and lots of too bright espresso days to want to go through that again any time soon. On the other hand, I have seen enough of your reviews to trust them and to see some similarities in tastes so perhaps I'll up my purchase quantity of #7 a bit.
Bottom line is that I'm enjoying my home blending experiences. Some have been quite good and others not so good. I have not gone as far as using Rwanda Robusta but I can recommend Nicaragua Limoncillo Pacamara Dry-Process as a totally off beat but delicious SO or blending addition to substitute for east african beans. Experiments are part of the fun. However, I do have some Ophiolite set for next week but the last pound is vauum packed and saved for the holidays.