Your Professional Profile will not get you the graphics link that comes with a commercial package, but nearly everything else on that page applies. You also have the choice for your Personal Web Page address. Convention dictates that your address is the first initial of your first name followed by your last name. The choice of yourname is up to you. Perhaps you prefer your business name instead of your name.
Availability is on a first come first serve basis.
So, submit your first and second choices. More than eight characters is fine. Upper and lower case characters do make a difference. The space allocation is admittedly small. But remember, the size restriction is established for uniformity of presentation and to encourage brevity.