Video Monitor for...

My new Bolt 3 with a GTX 1080Ti.

I just completed my order for a top level Bolt 3 and now am looking at monitors and wondering if I can get a little advice from you "experts."  I am VERY impressed by the MaximumPC review of 4K monitors and am leaning towards the Asus Proart PA329Q (because I can and want to).  I am a casual "gamer"  and prefer NON-online games.  I'm too old to play with the pros online have enough trouble with self contained games.

In fact, I can easily get "killed" by the "training" routines much less the actual game.  Anyway, a couple questions I have:

It appears that Display Port (DP 1.4) is the cable of choice for 4K hookups?
Can I expect the GTX 1080Ti Bolt 3 build to come with a cable, or do I have to order separately?
There are available HDMI connections but I don't expect to hook to a TV.
Finally, the GTX1080 Ti show that it can run 2 monitors.  Do I screw things up by running the 4K AND either a 1440 or 1080p monitor?

As you can tell, my first excursion into the High res world.

Thanks.
Arne

Wonderful Thank YOU!!