Or some thing like this

http://wh40k.lexicanum.com/wiki/Starhawk_Bomber

Not sure if its warp capable but still. And! There would be other ships not covered by the lore between a crew of 10k and 15... just cos the lore doesn't say so doesn't mean it doesn't exist. It's obvious! Small time traders and such can't afford a crew of 10k but maybe 500? W/e there would be other military vessels than 10 or 10k too. So... make something up that makes fking sense.