As I scroll through the forums every so often, I noticed and some what agree with the disappointment with the lack of armor skins vs outfits.
I'm not sure if this idea has been mentioned before, but a way around this could be to improve the hide/ show feature for armor and outfits.
Currently you have this option for only 4 armor slots; head, shoulders, gloves, and back. I'm sure most people understand how this feature works, but just in case you don't, simply click on the little check box for one of the mentioned pieces of gear to either have it appear on your avatar or not. Now for this idea to work you first need this option for each piece of armor, you will also need this for each part of the outfits too. The way this works is if you click hide on your head piece in your equipment menu/ page while having the head piece on your outfit page set to show, the outfit head piece will appear on your avatar while the equipment head piece will not and vice versa.
This will allow for us to mix and match different pieces of equipment with different pieces of outfits, while on a development side would increase sales of outfits!