Here's a map based on the original Defend. In order to get everything to work right I started out with the Defend map, but enlarged it and modified it so that it no longer resembles the original.
Its called under siege. Basically, you want to start in the top left position, then transport crew to all the abandoned stations and ships you can find. I dislike spending my time builing stuff, so I have everything prebuilt (at least for the federation).
All bases are surrounded by astroids, you must use wormholes to navigate. This map is most fun when playing against 6 hard enemies. Otherwise its way to easy to win. I know its kinda boring (i.e. no nebulas and stuff), but it slows down my computer enough as is.
If you have a slow computer you probably don't want this map.
Under Siege