Desktop system for work.

Bought those little Pioneer SP-BS22-LRs that Andrew Jones designed - couldn't pass them up for the price at Best Buy. Not bad for the 80 bucks I paid. I'm going to use them on a desk in my office at work and and I'm looking for a small DAC / amp combo. I want to do it on the somewhat cheap (under $500). Suggestions appreciated. 
iFi model or...

NAD D3020
I've been eyeballing the 3020. Very very tempting. 

An opportunity to look at Active Loudspeakers.
For example:Paradigm Shift Active Atom A2.
Be aware of the PC as a component with reference to signal source.
That is 'sound' varies between PC manufacturers.