This is on our planned features list, first we need to build support for custom .iso uploads and we will continue to build from there.
Are you sure that is what you want? Because when you upload an entire ISO image you are now asking for your own kernel to be run under a hypervisor. This is a heavyweight solution where a virtual CPU has to be created to talk with your kernel, and that costs more to run.
The VPS I have with SkySilk is basically a protected subfolder and my software is being run by a shared kernel. This uses much less CPU (in my personal experience), and ultimately that means cost savings for me as a customer. You might want to think more about what you really need.