Sorry, but both M4A/AAC audio and MP3 are both lossy audio codecs that throw out digital information from the original source material in order to create there smaller file size.
Even at 320kbps M4A and MP3 are not as good as a CD in sound quality.
However with that being said, at a bit rate of 192kbps and above, human ears can not tell the difference anyways. This is due to the fact, that M4A and MP3 only throw away the sounds that humans can't hear anyways.
If you want to play back flac files, then I would recommend that you download the free and highly rated VLC Media Player. (Audiophiles swear by it.)
Get it here: http://www.videolan.org/vlc/
If you want to put flac files onto your phone, then just get a audio converting program that can convert flac to mp3.
Cnet.com has a list of programs that can do this.
See here: http://download.cnet.com/windows/rippers-and-converting-software/?tag=rb_content;main
Hope this helps.
PS. MP3's and M4A's when encoded from lossless sources like CD's for example, will sound nearly 1 to 1 with a CD at 192kbps and above. (Though technically still inferior to audio CD's even as high as 320kbps.)