In all actuality, he needs both the DA and the
switcher since the
OP wants to add equipment beyond the single camera.
On that note, since you (
miller1446)want to have DVD, camera, and computer presentations projected, your switcher will also need to be a
scaler since the resolutions are different. The DA will split the single output from your switcher to the two projectors. If you want
preview and program, your switcher will need to have dual video processors, which will also allow you to have seamless switching. Otherwise, you will need each of your DVD players and your camera to have preview monitors with a loop-through to the switcher.
As for recording, you have a couple of options as well. You can take a feed off of your DA (if you place it close enough to your rack) or if your switcher has multiple outputs, then you will have the ability to record your live feed (along with any glitches that might happen). If you are looking at post-production editing, then you could either record directly at your camera or have the camera feed looping through a recorder prior to sending the signal to the switcher (though this could add significant
latency to the projected image). The rest of your media is already prepared for editing.
What kind of budget are you working with? This will significantly affect the type of equipment that is suggested.