"Fires of heaven" by BTRC is available now and has a 90 page spacecraft construction, combat, maintenance and operations rule section that could easily be used for EP ships.
Just leave out the FTL drive, use the lower tech components and you've got a good ship system for EP.
Hell, the rules even help with making rpg scale maps for the ships!
"I learned the hard way that if you take a stand on any issue, no matter how insignificant, people will line up around the block to kick your ass over it." -Jesse "the mind" Ventura.