I've tried a number of different amps with Wilson speakers and find that higher-current amps work the best. The Lamm Hybrid M1.2's should be on a short list, along with the robust ARC 210 mono's. The Atma-sphere models have amazing transparency but give up a little low end control to give you that. The Stereo VTL Siegfried might also be a consideration depending on budget. I had tried the 90W Lamm ML 1's (single ended) with the WP's and found the sound a bit soft and slowed down--stick with the hybrids in that family. I know the BAT VK 150 SE's have shown frequently and favorably with the 7's and 8's as well.
Good luck!