The awesome thing about the Sapphire XL's is that there aren't too many amps they won't work well on. That said, at $980, Vista Audio's i34 integrate tube amp is damned tough to beat. Provided you can live with 35 wpc, forget about Jolida, Prima Luna, Rogue, etc..
For solid state, the Naim Nait5i is a solid match, though a bit under-powered if you intend to 'rock out' on the XL's. Great musical mojo though. On the high power solid state side of town, I'd investigate options from the likes of Sim Audio, Bel Canto, Ayre, or even Blue Circle Audio (if you like a touch of warmth).