need suggestion on headphone amp for gradosr325

I'm considering grado's own headamp
but a friend says to check out
am considering the antique sound labs MG Head Mark II
and/or the Wheatfield HA-1....any feedback on these.

Also, will be using the grado's for BOTH home theatre and (varied, ie., rock, jazz, classical) listening and hear the
ear pads can get uncomfortable...any suggestions for making them less so for extended listening periods?

Many thanks
joe (aka Canali)
Also check out the Grace 901, but it's pricey ($1500). The Emmline H2 is also well respected. Neither one is tubes.