You could also take a level in warlock. The invocation See the Unseen grants darkvision plus the ability to see invisible, at all times. It's subject to dispel magic, but if it gets dispelled you can bring it back as a standard action.
In fact, it might be a good idea to go rogue/warlock instead of rogue/fighter. A lot of warlock invocations are of the self-buffing kind, and work well for a sneaky scouty type. The eldritch blast is a ranged touch attack, making you more likely to hit with your sneak attacks. And warlock abilities can be used in light armor without trouble.