Monitor for Mac Studio M3

Yes the Mac Studio supports those types of displays.

see > Connect a display to Mac Studio - Apple Support

One problem that might crop up is the quality of the Dell supplied USB-C cable.

If that is a problem, then consider a Thunderbolt 5 (USB-C) Pro cable into you budget.

https://www.apple.com/shop/product/mdw94am/a/thunderbolt-5-usb%E2%80%91c-pro-cable-1-m

The Dell 40 in ultra-wide display model U4025QW display is a

5120 by 2160 display (somewhat short of "standard 5K" height of 5120 by 2880)

that features 10 bits/color implemented using an 8 bits/color panel and FRC emulation.

interfaces include:

HDMI 2.1

DisplayPort 1.4

2x Thunderbolt-4 with up to 140 Watts power delivery

standard ThunderBolt cables are listed to 0.5 meters max, which that YouTi=ube video points out, barely extends being the side of the display.

Longer Thunderbolt cables must be ACTIVE cables, much more expensive, staring at US$125 and up.

Thunderbolt-5 cables have no different length limits, because these are not BOTH ThunderBolt-5 devices.

Is this the one? Looks like a good choice based on this review.

https://www.youtube.com/watch?v=nwXx1vqD1V8

I use a 32" 6K monitor which is very nice as well.