Which amps with B&W 800D's... Pass Labs or Classe?

I am finally down to the wire... I am considering either the Pass Labs X350.5, a pair of the X600's, or a pair of the Classe CA-M400's to power my B&W 800D's. I am having the hardest time making this decision. I love my music loud, and I listen to alot of large-scale symphonic music, choral music, jazz, and various recordings that are very grand in nature. I am planning on incorporating a center channel and surrounds eventually in a theater and multi-channel setup and I would like to use the same brand of amp for those speakers once I decide to add them. I have heard great things about all of the amps above, but I cannot make that final leap of faith. Are the Pass Labs amps and the CA-M400's from Classe in the same league? I would love to get the Omega Omicron monos, but the budget does not exist for those right now. If I get the Pass Labs X600's, I am considering upgrading to the X600.5's when the budget allows. I have heard great things about the class-a capability of the Pass Labs amps. I am not keen on bi-amping and I really need some help in making this decision. I look forward to your advice! Thanks.

-Dave