When my cherokee is on it has a low rumble that you can feel, especially at idle, it has a massive exhaust leak i know that but i was wondering if it would be anything else, happens all the time, neutral or not

Chances are that when you fix the rotted exhaust system and get it to stop hitting the frame the noise will go away.

BTW. Kudos for filling out the profile on your vehicle

thats what im hoping do you have any recommendations for what exhaust systems to look at?

You're going to get about 100 opinions. I've always just used Walker parts including their "stainless" muffler.
I've never really thought louder was cooler, or faster, but I'm long out of high school.

If you do it yourself, get the wide band clamps instead of the u-bolts. They seal better and you can actually remove or loosen them if you realign or replace things in the future.