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.