Hello, I'm a bit new here and looking for some quick travel advice. I have searched all over the internet but I still don't really know what exactly to do.

I'm flying from JFK to Grenada next weekend for a month and I have to bring my 20" all-in-one desktop so that I can work remotely while I am away. Originally I was just going to bubble wrap it tightly and pack it with my clothes in my suitcase and check it. Then after some research I found the ilugger so that I could carry it on board with me.
I called Delta (since they are who I will be flying with) and the woman told me my computer wouldn't be allowed as carry on b/c I cannot turn it on the way you can with a laptop. I thought that was a strange reason so a few days later I called and someone else told me that as long as it fits the size requirements it should be fine. But if I wanted to check it, then that was no issue either, but I would have to sign a liability waiver (which is fine).
But she suggested I call TSA directly and they told me I should REALLY carry it on b/c it is such an expensive item that it would be better off in my hands.
Still though, I am worried about it fitting the carry-on requirements b/c it is over the 22" x 14" x 9" (an ilugger being 20.5" x 19" x 6"). But I've read stories of people carrying this on with no trouble.

So I guess I have 2 questions- One being has anyone brought an all-in-one (be it a PC or Mac) on their flight as a carry-on or did they prefer to check it?
Two is- how did you pack it? Did you spend lots of money on a really nice carry-on case? Or just put together a homemade laptop bag? Is there something just as good as the ilugger but not as pricey?

Things to note:
-I will not ship this item, I don't have the money
-I did purchase very good traveler's insurance so I can cover the computer if it suffers any damages (I actually needed it more for the trip cancellation)

Any advice that anyone could give would be SUPER appreciated! Thanks!