RustySubmarine,
I consider Flakmonkey's NewInteriors essential with my GWX setup, but also give Ianmbecomelife's Merchant Fleet Mode a try...it is compatible with GWX and adds a lot to SH3. Read about it here:
http://www.subsim.com/radioroom/showthread.php?t=170741
Make sure you get the Merchant Fleet skins pack download as well...read about them in the thread above. Also take a look through the subsim download section for SH3 and you will find a number of other add on mods that are specifically for GWX. This should probably be a new topic so we don't clutter up Flakmonkeys mod thread.
Kelly621