A step up from Audio Refinement complete

What would be a step up from Audio Refinement complete amp?
I am planning to purchase a integrated amp for my sister.

I already gave her a pair of Epos M12. I have my sight on the Audio Refinement complete but would be willing to go for something a bit more.
In the same (sonic) vein, an YBA Passion Integre??
The YBA Integre DT, if you cannot go for the Passion. One killer 50 SS watts.
Your sister just might be content with the Audio Refinement Complete. You can get a good used one w/remote for about $550-600.00 here in the classifieds. With the extra money you save, upgrade your own system( or better yet,splurge on some music for both you and your sister). P.S. I have a complete integrated in my bedroom system and I'm very pleased with its musicality.