For Prowler
 

I'm not aware of a program which will batch convert and batch normalise volume at the same time. Best to normalise a batch of Mp3s using MP3 Gain:

http://mp3gain.sourceforge.net/

Then convert them with media Coder:

http://mediacoder.sourceforge.net/

Both programs are fast, easy and free

Audacity is superb, buy doesn't work in batches - single tracks only

Thanks, I'll give those a try.