I don't know that I would trust a receiver's claim of playing flacs. My Onkyo TX-NR906 supposedly will but it doesn't. To the best of my knowledge the Vista version of Windows Media Player's media server does not serve flacs natively. If memory serves there was a way to make it work but it was pretty sucky. That may have changed in Windows 7 but I have yet to see it referenced anywhere.
I've been ripping CDs and playing back flacs for years and have tried several solutions. I started out with a PC dedicated to music playback. I would do the rip on my main PC which has 3TB of RAID5 storage and then use GoodSync Pro to copy the music across my wireless N network to the dedicated PC in my music rack. The advantage to this is I have a backup of my rips in another room.
Pro: Excellent quality, music always backed up, and I could queue up hundreds of songs in Winamp.
Con: It was bulky and really required a keyboard wireless keyboard.
The solution that I now use is a
Western Digital TV Live. It has a much nicer menu system than my receiver and digital outputs to the receiver. The remote is simple to use and it can be controlled from a Logitech Harmony remote. Again I rip from my PC and use GoodSync to copy to an external hardrive on the WDTV Live. BTW I also use this to store and play rips of my favorite concert DVDs.
Pros: Small size, digital output, excellent user interface, tiny remote, Harmony compatible, accepts external drives, networkable. In the event of a fire I can grab the external drive as I run out the door.

Cons: Slow network transfers, requires you to create playlists to queue more than one album at a time.
Just a couple of tips, I use
dbPoweramp Reference to do my ripping. It's inexpensive and not only does a great job of ripping but it also automatically tags the rips and files your rips away on the drive according to your specifications. My next suggestion is even more important. I've been a computer tech for 20 years and I've seen way too many drives die. I store my rips on my PC, and on a dedicated home server, and on the external drive hanging from my WDTV Live. That way if any two die at the same time I don't have to spend a year ripping CDs again. Now that they have 1TB 2-1/2" external drives I'll also start keeping a copy in a safe deposit box.