Can anyone suggest best option for Profile Setup?

I have a multisite setup & I am looking to create multiple Profiles on the main site. Can anyone please tell me what the easiest & best solution is? I started to create the Profile Fields and one Field I have created is for the new user to select from the drop down box their type of Profile. Once they have done this & completed registration I would like each Profile type to have it's own design or set of Fields. Is this possible & how do I achieve it? Thanks.