Depends on the bit rate, number of bits (8 or 16) and mono- or stereo. Right now I can't remember the bandwidth of "Hi-Fi", but double that (the Nyquist frequency), and select the next higher rate from the rates that .wav files USUALLY use (11025, 22050, or 44100 Hz). 16-bit is nice, but most records have such lousy scratches and such that 8-bit is often as good. A 44100Hz 16-bit Stereo file is 16 times bigger than a 11025, 8-bit Mono file. Most compression techniques add audio artifacts (just like .jpg adds visual artifacts). Unless the records are stereo, use mono. Even if they are stereo, if the scenario does not benefit from the Stereo sensation, use mono anyway.
If you plan to "clean" any of the files (remove pop, click and needle hiss or wow and flutter) START with .wav files, and maybe share (or publish) the files in some sort of compressed format. Personally, I would want .wav so I can do the cleaning myself... I've done a lot of it.