Valve amps for Shahinian Obelisk ?

Hiya, can anyone recommend a proven set of valve mono power amps that will drive Obelisks properly ? Not an obvious combination (shahinian advise SS Bedini, Plinius and Dynavector amps) as they are rated at 6 ohms but apparantly spend a lot of time at 2 ohms.
Not really. I've read where some have tried Blue Circle.
That's all I've heard about. Does it have to be tube? What about SS amp and tube pre.
Good call on SS amp and tube pre...the newer tube amps like the new ARC150 or the CJ amps but intealled with the KT120 tubes apparently have quite a vice-like, SS-like grip and power, along with the midrange magic/transparency of good tubes.
I've been listening to a set of Obelisks with a modest ARC Classic-30 valve amp for years.... wonderful combination.