I've found out that SCM 10s are 80dB sensitive. that's quite insensitive speaker. high power amp would be advisable. however, in your situation you might just get away with a 50W outputted by Brio R. assuming your listening position is about 2m away from speakers (only 8 ft long room) and you don't listen at ear-splitting spls (I assumed 75dB mean spl plus allowing for 15dB of headroom, 75dB is actually quite loud so you need to slightly raise your voice when talking) 40 W is all you need not to strain the amp. in fact most of that power is needed to accomodate for the headroom because if you rule out the headroom you'll see that in order to get 75dB at listening position 2 m away from your 80dB speakers you need about 1W!. headroom is needed so dynamic music wouldn't clip. but the condition is you don't lisetn to music too loud. club volume levels are out of the question.
there's one more unknown of speaker impedance but I doubt your ATCs drop below 4-5 Ohms so you should be safe with Brio R in that regard too.