I think he wants an "upgraded" one (thus the "JKEnhanced" mod). Like with a higher face-count and better mats.
In which case, I'm stumped.
As for the ships, I'm pretty sure there's a program that converts XWA opts to 3dos. If you can find that, just ask around the XWAUP (or maybe GoZ studios) to see if they'll let you use one of theirs.