If you have a second iPad (and a network router), go for the network client approach.
Regarding the adapters: I had really bad experience with 3rd party hdmi adapters. The output quality of the hdmi signal was very bad compared to the original Apple adapter.
That sad, I also had an issue with the original adapter: Apparently it needs a new firmware for every new iOS version. And that firmware needs to be downloaded from the internet. So make sure to connect your adapter at home before a gig so that it can update its firmware if needed.