If it is any help, I would suggest a banner no bigger than 175 pixels in height. I think that would allow you enough creativity without hiding the important information. If you want I can try to make a few for you.
I would also work on the color scheme. I get that you are trying to make it have a 90s Nick vibe, but too much orange is very harsh on the eyes. Maybe instead of having orange for the background of the messages, maybe try an off white or really light peach color. I think having the page background orange is fine. Of course, you won't really know how it will look until you start playing with the colors. My suggestions could look terrible