how much cpu or two devices

That helps to know it's all muxed into one connection. The client is going to be on windows so this won't be an issue. I would use the same router as that instructable (I had seen that article), but the dlink one has a 4000mah battery instead of a 2000mah which is more suitable for the long exposures of astrophotography. When you say you made a build specifically for that guy can you elaborate on what is different from the standard ones listed on the downloads page?

So the reason the camera for star tracking is low res is because it mainly tracks one or more bright stars in the given field of view. It sends this via usb to a program running on a computer that the guide software that basically tracks the movement of stars across the sky. They move slowly in terms of what would be normal shutter speeds. But astrophotogrpahy is typically long exposure, sometimes 5 minutes or more. So any movement then makes star trails if the mount does not move with the stars. A second cable goes out of the guide webcam to the motorized mount that sends movement controls. Example is this model. http://www.optcorp.com/or-52064-starshoot-autoguider.html This webcam is mounted to the finder scope, while the actual DSLR is mounted to the main telescope. The camers typically run at higher fps (60+) because while things move slow across the sky that are far away, closer object like planets/close comets/eclipses, etc move relatively fast across the sky and require movement instructions to the mount at a quicker pace. The nicer lodestar cameras operate at up to 200fps for example for fast planetary tracking.

The liveview on the dslr is nice, but i really only want it long enough to setup the parameters and then set the long exposure off. After that I can just let the intervalometer do it's thing.

I do see the builds for that router, also there are the MT7620a ramips builds in the repo. I could build myself if needed. The 4000mah battery is the main draw here, as an imaging session can go most of the night. The cables aren't an issue in the summer, but in the winter it's much nicer to be inside a vehicle or building while your equipment is out imaging. Also there is no worries about camera shake from cables moving around, as even the tiniest of shake can screw up a 5minute exposure easily.

I should also note that I'm open to some other solutions for a device. This one just looks like it could be the cheapest. I had also though of something like an intel nuc with a battery or a netbook as the client device with an ad hoc connection to my host running the guide and live view software. I would like to keep it reasonably small since it needs to be portable but the telescope mount is sizeable enough to attach things to. The caveat is that guide cameras output to usb and the liveview on my camera is via usb, so i'm either still using something like virtualhere, or the client device must be something I can remote into that's reasonably powerful. Running virtualhere seems like the more portable option if it's speedy enough.