Unique-ARs are a new company which offer handguard making services. They will manufacture custom AR-15 handguard to your specifications. If you want a red handguard with a communist hammer and sickle design, no problem, they can do it (and have done it!). If you are not a designer, they can assist you in turning your idea into a handguard design.
They are also happy to manufacture private label handguards (meaning they will make it with your branding instead of theirs) so if you have a great idea, you can get them to make it and then sell it yourself under your own brandname.