I used what Jriver uses, which is APE, and it sounds great and from what I read it's similar to FLAC. I hate to complicate things so that is one of the reason I went with it, and it's too late as I sold the bulk of my over 20yr old collection.
Speaker System:Ascend Tower RAAL, Horizon RAAL center, Tower NrT rears
HT SSP: XMC-1
Amplification: XPA-5 G2
Source :Oppo 105D :HTPC 16TB Jriver 19: Tivo Premier:Apple TV2g :Roku2
Rack:Salamander:Synergy Model Triple 237:Synergy Model 402
Power Management:Panamax M5300-PM
I had used FLAC, because it is lossless and has tags. Six months ago I converted all my FLAC to Apple lossless, because I bought some Apple devices (which won't play FLAC). So FLAC, unless you use Apple.
When you rip, be sure to correct/edit/update the tags. JRiver and all other music programs use the tags to sort, index and database your music; trash in; trash out.
I use FLAC with Jriver. For me, WAV not including key metadata is a show stopper for that format. I had a lot ripped in WAV before I realized that tracks would not play back in the correct order due to this limitation of WAV.
Go FLAC and you won't regret anything.
XMC-1 DIRAC Full; Oppo 105/Roku Ultra to Panny AE4000 w/106" screen; UltraRendu to LH Labs Geek Pulse X-Infinity; nCore nc400's or Prima Luna Premium Prologue to Maggie 1.7's; Rythmik F25; XPA-5 to CC-470v3 Center/ERD-1's; Thorens TD166 MkII/Denon DL207/XPS-1; 5-zone Sonos w/Def Tech AW5500's @ deck/pool/master bath & Sony SS-MB105/Polk R10 @ great room & kitchen. Two headphone setups: Hifiberry/BasX A100 and Allo BOSS/Schiit Asgard 2 (each to Senn 600's). PC w/Airmotiv 3b's. Roon user.