iMac and iPad combo, or MacBook Air and iPad?

I need help. Here are the two paths I can take:

  1. Have a dedicated iMac at my desk for my main work (word processing, video editing, blah blah blah) and have an iPad as my go to mobile device (I've got mobile hotspot with my phone, so I don't have to worry about Wi-Fi struggles).
  2. Have a MacBook Air with an external monitor for my main work and have an iPad as my go to mobile device.

I'm a college student, so space is needed on my desk (which is why I even thought about the iMac). I'm not here to verify my thoughts on the matter, I'm just here to read comments from those who are in my same-ish situation, and by that I mean that you've got one of the two combos that I'm talking about. Anybody currently running an iMac and iPad combo? Vice-versa? Any advice on how those are working for you would be greatly appreciated.