You're pretty much just looking for an D/A converter. So when looking at device, make sure the converters are as good as possible. Unfortunately most device that have 4 outs also have many ins that usually have preamps. And all this extra stuff will drive up the price.
Not sure what you're willing to spend, but
here's one for $200
Specs Line Outputs (D/A):
Output Impedance 150 Ohms unbalanced, 300 Ohms balanced
Maximum Output Level +1.8dBV, unbalanced
+10.1dBu, balanced
Channel-to-Channel Crosstalk < -108dB
SNR -103dB, A-weighted
Dynamic Range 103dB, A-weighted
THD+N 0.005% (-86dB) @ -1dBFS, 1kHz
Frequency Response 20Hz to 20kHz, +/- 0.3dB @ 48kHz sample rate