First time to try high rez downloads - need advice

Hey Guys
I've been away for a while getting a new store open. Wow, things have really progressed here. I am still a quasi dunce on the computer end of things but fairly knowledgable on high end sound. I have spent a fair amount of time comparing things from a sonic perspective but have not delved into high resolution downloads. From what I can see they are still fairly limited in terms of selection, but I would like to experience some.

As I (think) I understand it, virtually all must be downloaded in FLAC and converted to AIFF, which is hopefully straight forward. For the record, the digital part of my system is a Mac mini maxed out on RAM with a SSD and Amarra running behind iTunes. The DAC's I would use for this would be either my Wavelength Cosecant or Ayre QB-9, both capable of 24/96 resolution. Both are quite good but sound different.

I checked the forums and couldn't find anything directly addressing the process. If I missed it, feel free to point it out to me. On a side note, I have a great, very knowledgable high end guy working with me. He is a vinyl junkie; I listen almost exclusively to computer based stuff. We seem to have infected one another. He has never heard digital this "right" and I forgot how good really good vinyl is.

Thanks in advance.

Rick