Ian, I've been doing some research and some hacking. I opted for the 2nd option as it was much less expensive. This could be useful for shooting pictures remotely, or showing live video on a TV or projector.
would be ideal, as it works from a DSLR (Nikon or Canon) and a device (iOS devices, Android devices, Mac and Windows computers, and the Kindle) Price is kind of high, yet it works out of the box. You will also need some adapter to output HDMI from iOS or Android. Apple has dedicated lightning and 30 pin to HDMI and power in connectors.
There is also an alternative for android devices and Canon / Nikon DSLRs. DSLRController
uses a $40 wifi router. You will need an android device, a DSLR and some basic tech skills to get it working. You will also need some adapter to output HDMI from Android to the TV or projector.
Some Android manufactures use one spec (MHL) while others use another spec (slimport) for micro usb to hdmi. Do some research to find out what spec your device uses. In the near future, ChromeCast may support screen mirroring, but right now you have to have a nexus 5 phone.