Hmmmm.
I'm not an expert on this, and I tend to use FLAC over WAV.......but I don't think that the album artwork is tied to the WAV file at all???
I think that the artwork may be part of the "meta-data". I'm pretty sure that I can link artwork to the few WAVs that I have, but like I said I don't use this format much, and I'm not an expert in this niche.
When you use EAC, when you rip a disc, it gives the option to search a database (you tell it what db you want to use) and let's you choose artwork from the db. You can set up EAC to rip as WAV or FLAC, and I believe the artwork works the same for each.
The main reason that I use FLAC is that it compresses the file (lossless compression) where WAV does no compression.
Edit: You should be able to convert WAV to FLAC pretty easily. When I use EAC, it seems that it natively rips as WAV, then I have an extension program that takes WAV, compresses to FLAC, then discards the original WAV.