I Had exactly the same symptoms ,on a GA-880GMA-USB3 ,The only difference was that I only had the main array and no other HDDs connected .
I went through the stages ,loaded drivers ,same as you ,and got to the "choose drive to load OS" Screen and got the same error .
I tried several times , if I remember correctly ,it worked in the end , when I got to that stage instead of just restarting ,I took a back step to the previous stage and it worked ,sorry I cannot remember exactly how I went back ,it was some time ago . I never really figured what the problem was but once it loaded the OS everything worked ok after that ,and I had forgotton all about it ,until I saw your post.