In theory you don't have any of it if you are not worried about breaking the law or you do not have e checks.
Depending on the type of brackets you have...you should be able to remove the smog pumps. You will have to get new belts to drive a/c, alt and power steer pump. If you go to autozone, they'll ask you with or without smog pump. Or just cut the ones you have to size and compare to picking up new ones. Or find a serpenteen system off a newer auto in a bone yard. If you have cash to burn, you could order a set up from Summit or a performance shop.
You would have to probably have to update the carb, maybe the intake if you plan on going without your egr. There are all kinds of crazy vacuum ports on the stock carb. You can pick up an edelbrock 600 cfm with electric choke for a little over $200. Keep you vacuum T in the manifold hook it back up, hook back up your vapor canistor lines (may have to cap the fuel bowl vapor line or two) and your distributor advance directly to the carb.
If you think about it, an engine needs fuel, fire and air to run.
All the other stuff is there to help the engine not be as bad for the environment. To Del's point ...so we can breathe easier.
You could always plant a tree if you find it hard to sleep at night.
I would get cats on it, especially if it is loud. All you need is to get pulled over and "the man" starts checking your exhaust.
I would imagine the fine would be quite high and once you show you are not compliant I would imagine you will have to put everything back to stock. I had a friend that happened to on a vette.
What ever you do, save everything you take off. That way if you need it or go to sell it...you got it.
My theory is...if it ain't broke, don't fix it. So if it is running well, I would suggest leaving it alone. If you are really worried about dressing it up, they do make all kinds of legal after market parts. It may cost a little more now, but save you some $ in the long run. Not to mention you'll make some tree huggers happy and you are obeying the law.