dbpoweramp does a data and offset check. If it says there was a match and no errors, you should not need to re-rip. It's always good to examine the report after a rip.
As for format, .wav sounds best for most DACs. Most people use FLAC or uncompressed FLAC because of the extensive tag handling. If you don't care about this, then rip to .wav. You can always convert back and forth without issues with dbpoweramp.
Steve N.
Empirical Audio