portable amp advice needed: dt880 (32ohm) + cowon j3

[Enzyme]

hi,
i recently purchased a pair of beyerdynamics dt880 (32ohm) headphones to run with my cowon j3, although i really like the sound they produce, when i run the j3 through my x-fi soundcard (effects off) i get a much deeper\fuller\active sound which to me feels more like the intended sound these headphones are designed to produce.
great for when im sat at the pc but not so good for picnics and bike rides etc.

which i believe leads me to the need for a small portable amp.

im looking to spend as little as possible while not degrading the sound quality, also battery runtime is important to me with the cowon running for a day or two before it needs recharging, if possible i'd like to try and match this.

i was reading a forum post about the pico slim, but damn thats pricey and im guessing overkill for this setup, although the battery life and small form factor seems perfect for my needs, its just a lil too expensive ><

i know theres a few people here that really know theyre s**t when it comes to this stuff, so can anyone suggest any options for me (preferably based on experience).

any advice will be deeply appreciated as through searching i just seem caught between cheap and nasty , dodgy chinese seller and velvety luxury models.

thanks in advance