Welcome to the site, lots of fun figuring out what you want in your trailer, then even more fun ahead when you get to use it.
If you do some searching and reading you will find lots of things people did, many of which were just a one off. Way too many to list actually. Like Jon said, if you have an idea you would like to incorporate, just ask Reace. He will either make it work, or let you know why he can't. Not sure what pricing is like now, but I found any upgrades I made to be a very reasonable cost.