Advice: visually the same dual monitors - different pannel requirements

so, I'm looking to change the setup I'm currently using.

I'd like to get 2 new monitors with two very different requirements, but I'd like them to look visually the same next to each other so it presents a good look and they line up together nicely.

I'd at a very high level like a gaming monitor with high response time - as good picture quality as possible and a second monitor which is more generic.
Connectivity, I must have one monitor (most likely the non-gaming one with mini-display port).

Ideal scenario

1 x 4k monitor - with display port, mini-display port, hdmi input, thin frame, no speakers.
1 x 2560x1400 monitor - with display port and hdmi input, thin frame no speakers, very high response rate for gaming and top picture, no speakers

Both should look the same in terms of visuals and external sizing, both should be vesa mountable.

Variations of that would be welcome, but that's the ideal situation, thin frame, one real estate, one gaming monitor that looks the same.

What are my options ?

1) If you aren't tiling one window across the two screens, do you need super thin bezels?
2) In my experience, monitors with speakers won't take audio data from the PC unless you connect the included 3.5mm cable (and if they do, there's bound to be an option in the menu to turn them off) - if you find one that meets the other requirements but has speakers, it'd be silly to disregard it

As someone who had multiple resolution monitors next to eachother... Its actually a right pain in the backside.

found 2 different dell monitors that are almost visually identical, but massively different panels, basically a gaming one and a 4k real estate screen, next to each other they look almost identical so keep the visual side the same, usability, it works superb so problem solved.