Well, my recommendations were based on the assumption that you want something cheap and neutral, and in retrospect, I totally recommended you stuff I've never even listened to before! Just a heads up, so that you don't go buying something on my word alone.
The Schiit Magni is pretty cheap at $100, and is generally known as the best bang for your buck.
The Objective 2 (or O2) by JDS Labs, I've heard, is a bit pricier, but makes up for it in sound quality.
Finally, the Fiio E12 has the power you need in a portable package! But, the sound quality is worse (still awesome though) than a Magni (so I've heard), while being more expensive.
The only real amp I've heard is the Starving Student amp by pmillet! It's a great desk hybrid tube amplifier, and relatively cheap. The thing is, it's a DIY amp, so you have to buy the components and solder them together yourself based off of the schematic. I made it mostly to teach myself soldering, so I didn't mind at all, and if you want to learn to DIY, I definitely recommend it!