You can give up on the WiFi, but you could still stream directly from your PC through ethernet to the 5308CI. That way you don't have to go to FAT, you can use NTFS.
The best thing about the Denon is you don't need to go uncompressed .wav, you can stream .flac files. None of the other receivers support .flac. If I had all the stuff on my 1TB drive in .wav format I'd be well over 1TB. Uncompressed mon, it's a waste of de space!
Unfortunately you can't stream 24-bit audio files regardless of whether you're using USB or Ethernet/Wifi, only 16-bit, which kinda put me off because a lot of the tapers these days record in 24-bit (live DMB shows for example) at 48/88.2/96/176.4 or 192 kHz. I wish they had added support for that, I would have been a lot more likely to try and get the Denon I wanted instead of settling, for now, for the TX-SR805.
As it goes I have to burn all my 24-bit shows to DVD-Audio, so the ability to stream audio as a concern kinda went out the window with the inability to do 24-bit.
I do use 1TB of storage though, but it's internal. In fact, and you should keep this in mind, I use 2 @ 1TB drives running in RAID1 for redundancy of data. I'm at around 550GB right now, so when I fill up I'll just add 2 more 1TB drives. Whenever one fails, I'll shut down the PC until it's replaced and then it'll immediately be mirrored. There is years of collecting music in those drives, I'm far too scared to keep them just on one HDD.