Onkyo 9555

I just purchased an Onkyo 9555, for a friend that doesnt know that much about hi end, but i though this amp could be a good starter in the hobby.
now iam facing the hunting for speakers, he likes thin towers in black to match his furniture, so i was suggesting silver minuets but they are book shelves. Thinking on Rega RS3, no idea about the synergy?
i am sure some of you own this amp or a while,
really appreciative of guidance towards speakers, matching gear, cables etc.
thanks a lot.