Flex 4: Descending vertical DataGroup?

Question

I am currently working on a Photoshop-like transformer application to work with DisplayObjects as layers. I have an ArrayCollection which serves as my data provider for my List of values, but the problem is that the items are appearing in ascending order in the List:

0 - Item 1
1 - Item 2
2 - Item 3
3 - Item 4

Since it's a layer manager application, I need the items to appear in descending order like so:

3 - Item 4
2 - Item 3
1 - Item 2
0 - Item 1

This is because layer 0 is at the bottom of the stack, whereas layer 3 is at the top, rather than the other way around which is the way Flex is currently displaying things.

I know that I can simply apply a Sort to my ArrayCollection to cause the items to be sorted in reverse order, but this breaks functionality in my application. I was wondering if it would be possible to essentially modify my Spark List or DataGroup to have the layout render items backwards. Does anyone know of a short cut by which to do this?