Umm, that I'd probably stat up using vehicle-type rules for movement and external weaponry, and then have a nice floorplan and run the interior as a dungeon.
Toss in a skill challenge or two (for things like "boarding it while it's on the move," "boarding it while it's on the move with nobody spotting you," and the ever-popular "boarding it while it's on the move, with nobody spotting you and keeping that annoying NPC sidekick who nobody likes but everybody needs alive.") and you'd have a ton of rolling funder.....