too many comments causing time out on page/post

I have a post that I need to keep the comments open for and it has over 2,000 comments. This morning I had to change the memory limit from 32 to 64 because I was getting a fatal memory error on the page. Once I switched it to 32 it was okay. Do you know if changing that number in the php will have a negative effect on the rest of the site in the long run after I close these comments later this month?

Also, does anyone know of a way to page the comments? It makes my readers scroll through many to leave a comment at the bottom.

Thanks so much!
Amber