Assuming I want to sell a hardware appliance with only my software on it, what do I need to do?
Google used to do this with the search appliance (don't know if they still do). VMWare should have a website like cafepress where you upload a logo, choose specs, and then give them an image and they dropship you a server with that on it.
Edits to this question are encouraged, for all the things I forgot.
On the hardware side, MBX or Rackable will almost do what you're looking for. As far as remoting into the box once you have it deployed, you'll either need to have it phone home as part of a user setup or have the user give you the info when they have a support call.
The actual mechanics of remoting in depend on the OS you use. Linux would be the easiest (in my mind) because I would just set up a reverse ssh tunnel using autossh to a jump host.
You'll also want to give a good deal of consideration to hardening the box, and the level of access you'll allow the end user to have.
Goolge still has it check it out here Here is another example, trixbox.
You need to make some decisions. For example:
Are you going to provide the hardware support? How much you want to price it? Requirements of the software? What is the brand?
Then build a prototype, you can head up to newegg.com and buy some parts. See how customers respond and if its a good idea. If things go well then you can contact ODMs, and check what it takes for them to develop your appliance and put your brand.
But first thing, take baby steps. Define the specs, design the system, develop various prototypes and see how your customers react. Actually VMWARE image could be the first prototype and might be the way to go. Just sell them the image and let your customers take care of the hardware.
One thing that might also help is if you could let us know what the appliance is? For example there are a number of companies who supply tills based on PCs where you can put your own OS on it.
You also need to think about OS, there are a number of them out there that could meet your needs from Windows CE and XP Embedded to custom linux Distros.