Personally, i think 1080p is enough.
Actually, you can play your PowerPoint presentations automatically without any click by setting transition and animation timings or rehearse timings.
As to output video format, if you are using PowerPoint 2010, you can output .wmv video with it. However, there are only 3 kinds of output resolution, and the largest size is 960*720, and the output video format is limited to .wmv.
If you want to output a higher resolution HD video, or DVD, even Blu-ray, it is recommended to use the ppt2dvd tool from Moyea, you can visit their website: http://www.dvd-ppt-slideshow.com/
to find it.