brake system question

I have a 1995 Chevy G20 van (v-8, 350, 5.7 liter engine. Gasoline, not diesel.) I need to replace the rotors and pads, but I am not sure which rotors to get.

When I look for the parts online, I find options for a vacuum boost system and a hydroboost system. How can I tell which system my van has, so I can get the proper rotors?

Thanks, in advance, for any help you can give me.

Look under the hood at the brake master cylinder. If you see a big, cylindrical drum just behind it, with one hose coming off it (like this blue picture) (http://www.howstuffworks.com/power-brake.htm) then you have a vacuum booster.

However, if you see a rectangular box with 2 or more hoses coming from it (like the first pic in this article) (http://stu-offroad.com/suspension/vanco/hydroboost-1.htm) then its hydroboost.

FWIW the vast majority of ordinary vans have a vacuum booster. The hydroboost is almost always found in some G30 one-ton vans and the heavy duty 'cab-and-chassis' version, which is used for cube vans, school buses, etc.

Thank you SOOO much MagicRat! Those pics helped tremendously, and I figured out that I have a vacuum boost system.

Now I can get the rotors and pads and get rid of the pulsing/shaking to a stop! :)