Alternatives to selecting valid value from a list of items

Question

I have a screen in Winforms where the users select a possible value from the right to the area on the left as shown. Both the sides are listview with category group headers. When the user wants to assign a value for the item in "My Choice 1" category they click on the row below (which looks like a hyperlink "click to assign") and it changes to italics with different text. This affects the listview on the right by disabling the items that are invalid for this category and also enables the checkbox mode. Then the user selects one of the enabled items by clicking on the checkbox then the value of the item is now displayed on the left and the italics in the link returns to normal.

My question is are there other alternatives to this kind of selection. Only one item from the left can be selected to assign to each category on the left. The user wants to view all items on the right. One think they don't like is that although the invalid items are disabled and not selectable the checkbox still remains. Usually there are 6 items per group and 2-6 groups on the right side but in theory unlimited but they will not be more than 20 in practise.

Edit: The Items are grouped on the right and that is why they cannot be a combobox. Also every item has an icon based on the type of the item which I haven't shown in the mockup. The icon is on the left of the item in each row. There are also action hyperlinks inside each group that allows to add items on the fly using a popup dialog, I have shown them in the mockup. I don't think a combobox can do this. Aligning the right and left is not possible as you can choose any one item from the right to one item on the left. As I said each category on right has exactly one item.

Context: Think like 3 people want to setup a party. Each person can add some drink, entree and mains as their favourite. The person's name is the group header on the right and the items are their choice of food. Now think that the party can have one each of drink, entree and mains (the group for choices on the left) to be selected from any one of the people in the party. This is a business rule. That is why this screen is there. If they want to change the drink then on clicking the link only the drink items will be enabled on the right with a checkbox (entree and mains disabled). Then from all the enabled drink items of all the people only one drink can be checked and that choice is then assigned on the right. Also from the left people can add more drinks, mains etc.

^{download bmml source – Wireframes created with Balsamiq Mockups}

Answer 1

Since you're working on WinForms that means that you're actually on a Windows Operating Systems. In your case with multiple choices I would go with the more conventional Windows style and use Add and Remove arrows, as the mockup below tries to explain.

^{download bmml source – Wireframes created with Balsamiq Mockups}

Most Windows users, and especially Power users, know how this control works, and are comfortable with it. You could also implement Category Tabs on the right hand side, just as the screenshot below from Office 2013 Preview: Customize Ribbon Option.

It's generally better to use a familiar control, in a known environment, than invent something new unknown. The user don't have to figure out a control they have seen before, 'cause they know how it works.