Novice needs Mac Mini and DAC advice

Stereo Boys, I really really need some advice. In the past 18 months, I've loaded all in on this hobby and in that short time span have gone from birth to a full blown, fairly high end system and now I'm integrating a Mac Mini server into the mix. My mind is blown with too much information and I'm losing it over which DAC will give me the best bang with a budget anywhere from $800 to $4000. I'm told that the Ayre and Wavelength don't really outperform the lower cost DACs by a huge margin. I need a shot of the truth. And I'm looking for plug and play. I'm not that conversant with all the technical science involved in all of this. I just want a clean, high res sound. Please help!!