Mullard EL34 as a choice for your amp.

El 34s are GREAT for small, intimate music. However, they don't rock and they don't do large scale well/

Thanks to ICE technology (at least when it's done right) you no longer need tube amplifcation. See Wyred4Sound amps

You might gain tube warmth from a tube preamp or tube output of your source

Are you talking NOS or reissues?

Mrjstark-- congrats on having a very nice set of mono's.
As configured--each of your mono's with a quad of EL-34/6CA7 are capable of some major dynamic swings and LOUD playback levels with rock and large scale music. This is especially true if your speakers are above 8 ohm impedance and 91db efficiency. Many of the great guitar tube head amps use EL34's and believe me when I tell you--they rock.
As far as Mullard old stock tubes are concerned (not re-issues) they are known to last many thousands of hours as well as having a more tubey old school sound than the more modern production. I would recommend some of the newer production tubes for you as two matched quads of original Mullards will run you Approx. $800.00 The new Groove Tube Mullard reissue are claimed to be very good. It would be a good idea to state the type of sound you are shooting for.