^ Yeah, that's them. That's unfortunate they're more expensive over there.
They have XLR, 1/4", and RCA inputs so you can plug anything into them. From your iMac you would use a Y-cable to go from 1/8" stereo mini to dual RCA plugs. Keep in mind that these kind of speakers do not have a volume control (at least not an easily accessibly one) - you would control the volume through your iMac or with an external recording interface (for example, the Focusrite you see in my sig).