When looking for inspiration on a creative server my friend owns, I noticed that they had heads, but not just the normal animal or mob heads. They had heads such as tiger heads, or clocks, even toasters. Now, as it was a creative server they had normal animal heads as well, but since we already have them they wouldn't need to be added. My suggestion is that we have a command such as /skull or /head to open a window, with multiple pages you can navigate with the click of a head, or maybe have separate commands for each page. Each head would cost rupees or tokens. They could cost 10r a piece, or maybe 5 tokens each. If you wanted 5 hamburgers, you would have to pay 50 rupees or 25 tokens. You would just click the hamburger 5 times, and you would get charged each click on the head. Let me know if you like the idea!
You never know, maybe times have changed. I response to this, maybe there could be some rarer heads that cost more? Like there could be special limited edition ones for holidays, i.e. a turkey for Thanksgiving, Santa for Christmas, a Bunny for Easter, etc. I think this is a great idea. +1
The way you can obtain these heads is by changing your skin to the head of your choice, then obtaining it through vanilla means. Change the skin, Rinse and repeat. The direct selection of a head with a command like this suggestion implies will not be happening.