Ideally, you need an amp that'll deliver a high current and a good power supply to control the speaker drivers. The Roksan's rated at 120w, so it might be worth a go. Alternatively, do consider - if only to discard - the AV amps from Onkyo which Noel Keywood at Hi Fi World rates well in his reviews. The TX-SR608 (previous generation model) apparently has a nice smooth sound to it (very listenable, not brash by all accounts) and of course, the other great thing is you can assign the onboard amps (being multichannel) so you can bi-amp. :bounce:
There's a common wisdom that AV amps don't cut the mustard against stereo ones and while that may have been true once upon a time, I think that gap's decreasing all the time to the point that, if it exists at all with some brands (like Onkyo for isntance), it's decreasing.
The other benefit of course is not only are AV amps multichannel, they're multi-format and usually offer a decent DAC option that will take other inputs. If that functionality is on your radar or you have some SACD or DVD-A discs or other hi-res formats to play with, then yer typical integrated is left far behind.