ASP.NET MVC ViewModel to Hold Lists & "Images or YouTube URL's"

I'm posting this question because I do not know the best/correct way of doing the following.

My team-mate (the designer) sent me a good looking design that includes a wizard for adding new items (for auction). The user has to fill in all the required details which include the title, description, starting price...etc AND a list of tags (up to 4 tags - chosen from the database, will use auto complete) as well as a list of up to 3 images/youtube url's (for the sake of better explanation check this image out: http://i55.tinypic.com/2v11zzr.png)

Ok so I figured out how I should do the wizard ( reference: how to make a wizard with ASP.Net MVC) but I'm not sure about how to collect t开发者_JAVA技巧he lists and the images/url's. Here's what I'm thinking:

1. For the images/url's, I should create a parent view model from which two sub-classes (ImageViewModel & YoutubeUrlViewModel) would inherit from and then in the controller action when I parse the post data, I would check to see the instance of the parent view model and act accordingly.

2. Now about the lists, I'm not sure whether I should include a List in my view model or whether I should include 4 string properties representing the tags (the same will apply to the list of images/url's).

So what's the best way of doing this?

And Haacked to the rescue: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx

:)