Don't let things like jack-type affect your preferences. A 1/4" to 1/8" adapter is truly a pain, but you can always make, or have someone make for you, a cable for it. Not a big deal either way.
Other than that, from technical specifications (sensitivity of the headphone vs. load of the DAC) I think it seems like this one won't be able to driver them very loud, so if you have some low volume live shows I think you might need some more volume, more power for the headphone. They don't charge (that) much for the amp, so it makes sense in this regard too. Try something else. If you have some extra free time I suggest you dig into Head-Fi for awhile, you'll find wide discussions about amplifiers on there. Give it a try.