Back in 2001 at a store in Denver heard both the Plinius 8150 and the Classe CAP 150 in a side by side comparison. The Plinius was a special order for a customer while the Classe 150 was there as a trade in. Both units were played through a Wadia CDP and the speakers were floorstanding Usher. I cannot really recommend either one of these for rock music. These units excel at jazz and classical. Rock sounds okay through them, but to my ears neither really involved the listener in rock music. Although to be honest the Plinius was brand new and was being tested before delivery. Once it has logged some hours it may have been acceptable for rock music.
One intergrated that came through here about two years ago that I can recommend for that genre of music is the Musical Fidelity A 220. Puts out 50 WRMS per channel at 8 ohms and doubles that to 100 WRMS at 4 ohms. Biased heavily into Class A output and runs at about 130 degrees farenheit. Needs plenty of space to ventilate the heat generated by the A 220. So you may want to put this one on your short list. Also the Denon PMA 2000 IVR is a fine choice, does not run as hot as the Musical Fidelity A220. The Denon delivers 80 WRMS into 8 ohms and 160 WRMS into 4 ohms. The more I think about it the Denon just may be what your looking for, based upon the information provided by your post.