MPEG-1, MOV or WMV?
You don't have to decide when you buy — both SD & HD versions include all three formats.
MPEG-1 is, most likely, not the best format for you. It will, however, work on any presentation software but can be “clunky” on a Mac.
Windows Media (WMV) is a nice compression for PC users. It typically works much better than MPEG on Windows.
Quicktime (MOV) is the best option if you're using a Mac, or Pro Presenter or Media Shout on a PC.
Unless you've converted your whole setup to high definition (HD), standard definition (SD) is probably for you.