If the passport copy is notarised, you do NOT need to send his birth certificate as well.
Alternatively, if you are sending the birth certificate, there is no need to get the passport copy notarised.
Personally, I would use a colour copy of his passport photo page, but I don't think there's anything in the rules that specifies that it has to be in colour.
I would assume it's okay for his accountant to do it, but I don't know for definite.
So you have 3 options for providing his passport
1) His actual passport (not recommended in case he needs it)
2) A notarised copy of his passport photo page (no birth certificate needed)
3) A regular photocopy of his passport photo page, plus his original, long-form A4-size birth certificate to verify the information on the passport photocopy (this is the only circumstance in which is birth certificate would need to be included)