First thing to know about membership is that it has nothing to do with Names, addresses, etc... It's strictly about userid's, usernames, passwords, and authentication. That's it. Don't try to extend it to add names and addresses, that's not what it's for.
Instead, you simply create your own "UserProfile" table or whatever you want to call it. This table should be keyed on the ProviderUserKey provided by the membership provider. Then you need only lookup whatever data you want in your UserProfile table without ever having to modify anything to do with Membership.
So in your case, you can use the standard membership provider, which is keyed on a GUID. Then create a table called UserProfile that has 3 columns. UserId (uniqueidentifier), StreetName, and PostalCode.
In your application, you call Membership.GetUser().ProviderUserKey and use this as the key to lookup data in your UserProfile table. This is fast, simple, and requires no custom modification to Membership.
In your AccountController.Register method, you would, after creating the membership user, also create a UserProfile record with users ProviderUserKey, and the information you want stored.