Is it possible to download 2-3 suits for Dead Space from xbox live and be able to change between them?

I was thinking about downloading the military pack, the tank suit, and the astro suit. I've heard that you when you get one you can't change back to another suit and you are stuck with that one. But I've seen somebody on youtube change between all of the suits so I'm not sure if this is true or not. Also for the military pack it says it powers up all of the weapons in the game. But if you download the suit at the beginning of the game does that mean all the weapons will have extra power when you get them or do you have to download it when you have all weapons for it to take effect. Thanks.