i recently found out my throttle body on my 2000 neon was plastic.., i was wondering if a 1gen throttle body would work on it, or if not, is the auto throttle body from a 2gen neon larger than a 5 speed one?

The throttle bodies are not compatible between 1st gen and 2nd gen. There are adapters and special circumstances that you could interchange them, but it is a technical discussion beyond your question.
I don't know if there is a difference in the TB for manual or auto in the 2nd gen, there is in the first gen (49mm vs 52mm).

oh, alrite..haha.., i guess i'll just have to keep it like that for awhile till i save up some money..lol