Dust cover for lens and body?

I was doing some photography in a dusty environment a while back, and my kit 18-55 IS lens feels a tiny bit "gritty" in the zoom ring. I may be shooting in another (indoor) dusty location tomorrow and/or Sunday, but now I have a new 7D and 70-200 2.8 II and don't want anything to happen to them.

What should I do to cover my gear so that it doesn't get dust inside, like my kit lens?

UV cover and a 1 gallon zip-lock bag.

How dusty is this place gonna be? The 70-200 should be fine. A UV filters not a bad idea. Makes a scratch cleaning it not hurt the wallet. The 7D isn't as weather sheilded as the 1D series but does have more seals than the rebel line. You can always go grab a cheap rain cover if your that worried about it. The kit lens are crap when it comes to getting gunk in them.