You can have got a big line of them or only make the one and only (for example for a anniversary present). There is lots of opportunities to do that. Many businesses specialized in making bicycle equipment and a large number of creators could draw a project or already construct a part or whole bicycle. Today lots of people are gfascinated by fantasy books like the Witcher, the LOTR or the Games of Thrones, so we may have vehicles with maighty dragons, famous swords, elvish inscriptions or crows, they look magnificient in the cities.
Nevertheless it can be colours of your city football team or a well-known band or something completely different. It only depends of your imagination and preferences and naturally it is about a specific brand, material which you will choose. The Internet is a forceful device for these sort of activity, it may help, but as well ruin even an excellent project. It is good to have got a person or a firm who going to support you with your plans.