Headphone amp advice

I am looking for a good headphone amp, probably tube. I will be using it mainly for recordings from my main vinyl rig. The Korg Mr-1, recently bought, makes these recordings much better than my earlier recording systems (PCM computer sound card, DAT, Revox A77), so headphone amps get interesting. I use Sennheiser 600 and Shure E3 headphones. This may change, but one point now is to drive the Senns to best effect.

I've been looking at several alternatives:
The Small-dot mk3, the Darkvoice SE, Lisa III. Haven't heard them, just from googling. Of these, possibly the Darkvoice gives the sound I am after.

However, these are non-portable designs, and I would like something more portable. In this area, the TTVJ hybrid portable, possibly the s-state Nuforce icon, are among the contenders.

Your advice is welcome.