Hey "V" (or whatever your real name is)..
Sounds like a nice topic for your dissertation, one im sure you will enjoy alot.
An old friend of mine, Liam, did a thesis on the differences with Dark & Long live / studio as part of his International Baccalaureate - this is the old thread, however the link to the actual thesis is old and expired
http://www.borndirty.org/forums/showthread.php?t=2501
As far as a full complete list of Rez / Cowgirl, here are the ones i could find from the "songography":
p { margin-bottom: 0.21cm; } cowgirl (album) 08:29 v, cd, cs
cowgirl (bedrock mix) 11:50 v, cd, cde
cowgirl (bedrock radio edit) 4:16 cd
cowgirl (cd single album) 08:55 v, cd, cs
cowgirl (future shock mix) 08:27 cd
cowgirl (future shock mix) 09:30 v, cd, cde
cowgirl (irish pub in kyoto mix) 11:45 v, cd
cowgirl (live radio edit) 03:39 cd, cde
cowgirl (winjer mix) 06:25 v, cd
rez 09:55 v, cd
Im sure there are loads more, including all the various LHN versions... but it should give you an idea.
As far as live recordings, with a massive number of bootlegs in circulation, most of them have Rez / Cowgirl in some form stretching from 1994 - 2010 - your best bet would be to join / explore
rtsr trade to get the stuff you need.
Hope that helps a little bit.