Any way to listen to wav or high bit files with anything approaching audiophile sound?

Forgive the question, but this is my first time posting on Audiogon in a few years and I'm not up on some of the latest technology.  I'm doing a project where I'm going through as much music as possible for a blog I'll be creating where I find my 1,000 favorite albums of all time and ranking them.  I'm most of the way through my thousands of CD's (don't do LP's), and I have decent audiophile equipment, though nothing top of the line.

For other music, I'm going to have to listen to it online or purchase a digital version of the music, as there's no way I can afford to buy thousands more cd's, or they're out of print on cd's (as much of the music I love that I don't have is somewhat obscure), or they never existed on cd.  Some albums I know I won't be able to find. 

First off, is there a way to legally find more obscure albums online other than illegal downloading? 

Secondly, is there ANY way to listen to said music in anything remotely approaching audiophile sound quality?  Does it have to be a certain file type or bit rate?  I've always stayed away from digital files in the past, but now I kind of need them.  Is there some kind of audiophile digital storage device where I can download music to and play it on my stereo system?  I'm pretty ignorant about these things, so again forgive me, and any help would be appreciated.  I don't expect the music to sound quite as high fidelity as using cd's on audiophile equipment, but what are my options to get as close as possible?