Hi ! That looks like a nice set up.
1. Generally you are looking for a 1080p monitor, its really worth researching for your self. I would look for something Gsync compatible if its within the budget. Look into VRR (Gsync and Freesync) there are many articles explaining it better then I can here. Some monitors are not officially Gsync compatible as you have to pay Nvidia for certification but they work anyway. Only way to know that it searching the internet for others with that model monitor on forums or reviews. 120HZ or over is a big plus, but there are many 75hz 1080p monitors for cheap now so that would be a minimum for me.
2. The best program for monitoring everything in one place IMO is HWINFO. I also like to use GPUZ and Realtemp because they are easier to read at a glance on the desktop. You'll find them easily in Google, theyre old and trusted programs. Many people use MSI Afterburner, it works with all graphics cards MSI or not.
For a whole system stress test, and to do some potential good at the same time I can recommend Folding@Home
. PCG has a team too. You can complete a unit or two on the CPU and GPU monitoring temps of course, do a little good and stress test at the same time.
For benchmarking the graphics card, 3d Mark is good. There's a free version in Steam, but you'd need to pay for a lot of the features. Theres also the Uniengines, Heaven, Superposition. You used to be able to loop Heaven to stress test but it looks like thats behind a $15 pay wall now unfortunately.
Another utility Ive been using recently as a bonus is Fan Control.
I generally dislike the motherbpard manufacturers solutions for controlling system fans and this is a lightweight and comprehensive program that allows you to create fan profiles based on different temperatures in the system.
There's a start, let us know if you have more questions.