Well, EAC can transcode to FLAC on the fly as well. FLAC is completely lossless. Yeah, disk space isn't terribly expensive, but I do get some savings by using FLAC (save about 30%). Finally, for me, the most important thing about FLAC is that it allows you to utelize the mp3-style tags for artist, album, track, etc. I don't think that .wav will allow this at all (I tried, but there may be some type of add-on at this point). In my opinion, you simply have to have the tags.
I have all my music ripped to FLAC, and it streams to my preamp via a Dell PC that is directly connected to that preamp. If you are making an HTPC that will connect to the PC directly, then you would most likely connect the digital out of your soundcard directly to the preamp/receiver. If your PC is far away from your preamp/receiver, then the Airport Express is an idea. Same with the Squeezebox. If you're budget-conscious, I've seen the Sonos work very nicely -- it's much, much cooler than the other two.
Good luck either way.