thinking of switching from conrad johnson......

trying to decide between pass x250.8 or plinius sb 30, was looking at the cj premier 350 or the McCormack dna 500, but these amps are getting a little long in the tooth.  any suggestion and your experience with these two amps would help.  and what pre amp would work best with them.  since not many preamp companies are left.  and any feedback from whilecamaross is very much welcomed......thanks in advance.
Re: Herron Audio, resale may not be the best but according to a friend of mine, absolutely wonderful gear and a true gentleman to deal with.

Supremely musical, reasonably priced, manufactured by a true believer.
Seek out reviews on the web. Everyone who hears loves it.

yeah sfall, that's my thinking as well.  talked with different companies about a change, (dan, w/modwright, jeff, w/cj, I cant think of her name w/vtl, to name a few.  what do you recommend) decided to get pv 12 mod instead, then switched to amp.  thus my question, do you know anything about the two amps  (pass x250.8 vs plinius sb 301)  let me know.
VAC Phi 300 or two Phi 200s if you can afford it.  I've listened to the 300 extensively.  Great amp all around.  VTL 6.5...good luck finding a better preamp , particularly with a remote.

Plus, Kevin Hayes is great to deal with.
I own a Premier 350 and find it anything but old sounding.  The amp has been a number of reviewers "reference" piece.  They need to change to have a current model item for appearances but tend to hold on to the P350.  It's my backup amp for my c-j LP140 monoblock tube amps but I like to bring it in occasionally for it's more dynamic bass and transients.  There's nothing rolled off about it's highs. Seems to me the biggest difference between the amps you're considering is price.  A P350 will be a lot cheaper than the Pass.  
Also... the P350 has only single ended (not balanced) inputs while the Pass is balanced I believe so you'll want to consider cables and matching the output of the preamp when you make your second purchase of a pre.