good headphone amp/preamp?


OK, looking to get a headphone amp for Senn HD 600s that might also do duty as a preamp running with my ATI 1502 or Mcintosh 250 and Ohm Walsh 2s given some space issues? I saw writeups on a couple of ideas in Stereophile...Little Dot, Music Hall...Chinese tubes for small $. Also, have seen things on the 'gon, like Canary. Looking for something under $500...$300 might be better. Any input is appreciated as I will be bying off the net as I wont find it out here in HI. If it is only good as a headhpone amp thats ok too as thats my primary need. I listen to lots of jazz, acoustic, female vocals,guitar and piano, 70s singer songwriters.
joekapahulu
Haven't heard it, but what about the new Musical Fidelity M1HPA? (http://www.musicalfidelity.com/products/M1-Series/M1HPA/M1HPA.asp)
I would look at Woo and Decware. They may be a little above your budget but resale value is very good on headphone amps and many have preamp outs. You might also pose this question on Head-fi, where headphone junkies hang out discussing the latest and greatest giant killers in the world of headphone amps. I am sure they will recommend something within your budget.
Mcondon, thz for the tip on Headfi....apparently I have lived in an isolated world.