Hi, OPUS your screen is ~86.4 PPI at 1280x720. https://www.sven.de/dpi/
Specs say you can output 2560 by 1600 pixels
to an external display, via mini Display Port (mDP). A 27" 2K screen is ~109 PPI- for me this is about my ideal PPI, but it sounds like it's too small for your preferences.
Since it sounds like you'd enjoy bigger scaling, getting a 1080p TV might be better for you, since it'll be blown up bigger, but using a TV as a monitor carries some caveats: make sure it can display 4:4:4 chroma on the input you'll be using,
and set the input type as "PC," otherwise text will be blurry, and it will feel less crisp than a monitor. See details here
. If you need to output to an HDMI port on the TV, you need to make sure you buy a mDP to HDMI adapter that can output 1080p at 60 Hz
. If you get one that can only handle 30 Hz, you'll see the lag when dragging windows- it's annoying. Short summary is only buy a TV off a list of monitors rated to work well as a monitor. Of course, you don't have to worry about this junk if you buy a 2K monitor with a DP input.
I have used that Dell 4K monitor at work- it looks fantastic. Scaling shenanigans are more of a problem in Windows than on MacOS, but I've found that I prefer using a 2K monitor at native scaling over 125% scaling (sounds like you'd need more) on a 4K- I actually stopped using the 4K and went back to my old 27" 2K IPS. In my experience, scaling is a bit of a crapshoot, and certain output/monitor combos work better than others, so my personal preference is to use native scaling when I can.
I'd suggest looking at a 32" 2K screen as an alternative. I've got a Phillips BDM3270QP2 - a 32" 2560x1440 monitor, making it 92 PPI. There's a couple other ones to choose from on amazon. I'm connected to it via a cheap Amazon-brand mDP to DP cable, outputting at 2560x1440 from a (newer) macbook pro. Looks great, has a nice adjustable stand with an integrated USB hub. $350.