I've mashed the two up pretty successfully in my ongoing planar-themed campaign. In addition to mining all the resources folks listed above, I also took the "Rock of Bral" from Spelljammer and moved it to the Astral, giving it a magically contained time and bio-sphere, allowing it to be the main hub for Planesjammer. I added a few portals to the Outlands and other locales to the Rock, to better connect it to the Planescape areas.
Also, if you're not adverse to adapting from non-DND sources, I'd recommend checking out the old Stormbringer adventure "Rogue Mistress", which centers around a dimension-hopping pirate ship.