It's a wonderful idea. For red eclipse I tried to change the parameters of weapons that they were close to realism. Here's a link to the configuration variables http://camper.narod.ru/download/re/rac4.cfg .
Models can take to start from open sources, such as: http://www.md2.sitters-electronics.nl/
also quadropolis.us
May try to interest developers assaultcube reloaded http://acr.victorz.ca/ ?
Openarena positioning itself as a game with open resources and were examples models transfer of it in the cube 2. Beret very good model http://openarena.wikia.com/wiki/Beret