Hi! I'm a graphic design and advertising student at Iowa State University and would love to help you out. I currently work as a the web developer for www.foundation.iastate.edu.
I also maintain our social media sites, though we don't really have as much design freedom to create a cool youtube channel like smosh's.
I am on youtube several times a week monitoring our channel, and I've noticed they've added an appearance upgrade since I last seriously worked on a channel. I know you can't have a banner like Smosh has without becoming a YouTube partner, but I will help you do your best with what you got.
Check the pm for example work.