Headphone Amp/Dac reccomendation

I am looking for a usb dac/amp combo to replace my ASUS Xonar ST. My budget is ~$300 USD.
I would like 1/4" output, RCA output(to a receiver for speakers), usb input and either RCA or optical input. If it could play all inputs at the same time it would be nice but I can live without it.

I have found the Schiit uber stack which seems to meet my needs perfectly but I wanted to know if there were any other recommendations.

The only problems I have with my current card are that because I have SLI, sometimes I get EMI, and the temperature of my first gpu gets really hot due to the card blocking the fans.

The Schiit Stack is pretty much one of the best bang-for-the-buck setups out there. You can't get much more for the money, and as you said it sounds like it's exactly what you want.

Yeup that is about your best bet for your budget and situation.

I have a pile of schiit and its the best schiit I've ever pumped into my ears

I personally use the Monoprice Desktop Headphone Amplifier: http://www.monoprice.com/product?p_id=11567

Has everything you require (except all inputs being played at the same time), great sound quality, nice aesthetic and is well under your budget, meaning you could get something else nice on the side if you wanted too :D