A very high profile Prof. A recommended me to another high profile Prof. B to do some work for him. While normally as a graduate I should be very thankful and jump on this, I simply cannot do the work asked due to time and I also believe there would be a more suitable candidate for the work. Prof A's recommendations hold very high weight in the field I work in (his previous recommendation got me a job as an undergraduate). I feel that Prof A may have misunderstood my skills (he confused Java programming with Java web programming essentially). Prof A knows me somewhat well (I work for him currently), so perhaps this is why he recommended me.
How do I turn down Prof B's request in a polite manner without losing any face to myself or Prof A? In my response, should I also forward candidates whom I think would be able to do the work (e.g. cc them in the email)?