In the original Dead Space, the only suits you get to keep are the downloadable ones. If you really like the look of one suit, but want to upgrade your RIG for better damage reduction and inventory space, you'll have to choose. The military outfit is cool and all, but after a couple rounds in new game plus, you're might start missing your old engineering suit. This was fixed in later games, where the upgrades for an outfit were permanent, allowing you to keep all of them in your safe to swap out on the fly.