The Brio Trio R is 50W/Ch which should be sufficient to drive most speakers. Unless you are really monitoring at a very loud level, you'll probably only use 10 watts or so. I have a 50W/Ch Bryston amp driving an old pair of IMF speakers which are not very efficient, and for the clipping LEDs to fire, it's incredibly loud, and pumping out heavy bass.
BTW the Rega is designed to run on either 115 or 230V, so you can run either in the US or UK, just need the appropriate power cord, which should be supplied from the dealer.