[Twenty Twelve] Comment box top of page

Hey all,

First of all: I’m using a child theme. Since I’m having a guestbook with many posts, I would like to have the comment box at the top of the page in stead of at the bottom. Does anyone know how to do this?

Second: does anyone know a good plugin which I can use for a guestbook? I don’t like the layout of the comments. Twenty Eleven has nice speech bubbles, Twenty Twelve doesn’t have that, it’s just white and boring. I would like to modify the lay-out.

This is one of my sites, it’s using Twenty Eleven, but I think Twenty Eleven and Twenty Twelve need the same code for these changes?
https://www.wilmawestenberg.nl/gastenboek

Thank you in advance!