New boats? Maybe the Tuff 20 but 6 foot beam is narrow . I had a 14 ft Jet boat a long time ago that had a 7 foot beam

This is available and exactly 22 x 6

​​​22 Chaudron
https://norwestermarinegroup.com/inventory

I’m aiming to set this up as a fishing rig, likely a side console. Something like the Nitra 22 SSO, maybe with a bimini or T-top. A flats boat is often suggested in the 60–140hp range, but we’re not bonefish anglers—we usually fish slightly deeper water for redfish, seatrout, sheepshead, and so on. I also want more deadrise than a typical flats boat for handling chop.

Budget-wise, my dad is willing to spend whatever it takes, but he’s not really saving for retirement, so I’m trying to keep the costs from getting out of hand. The smarter choice might be buying a used 20ft SeaCraft or something similar, but I like a challenge. I work in the industry and have done rebuilds before, so I'm going to find a cheap hull and fix it up. I know I won’t recoup what I put into it, but I’m fine with that.

I have never examined one up close, just seen them at a distance. That said, most Nordic performance hulls come out of a small outboard, high fuel price, offshore racing environment.

They are generally light and strong, but lacking in the fit-and-finish and bling department compared to American boats. Decks are often not built not to flex when stepped on, to reduce weight. If they flex a little when stepped on by a 72 kg Norwegian on a salmon-rich diet, they will flex a lot when stepped on by a 102 kg American on a McGriddle-rich diet.

I would expect that to apply to Nitra as well.

E.g. the Hot Boats review of a Norwegian cat many years ago said something along the lines of "Supposedly, the boat was equipped with $5000 of race rigging, but we could not see any". However, the $5000 race package that the review referred to was a different lamination scheduled that included more divinylcell and less wood. It was not about billet parts.

I don’t understand the need to be that skinny if your fishing?
Why not rebuild a mid 70’s 222 Aquasport?

I prefer a narrow hull. A 22 Nitra with a 115hp can reach around 60mph, whereas an Aquasport with the same power is lucky to do half that. You could put a 225 on the Aquasport to hit 60, but that’s not what I’m after. Plus, the extra deadrise on the Nitra makes for a smoother ride in the chop.

When it comes to fuel costs, they introduce friction that can keep you off the water. If it’s going to cost me $100 in gas just to see if the fish are biting, or if the weather’s decent, or if I only have an hour before dark, I might hesitate. But if the fuel bill is closer to $50, I’m more inclined to head out. For me, that’s just a mental trick to spend more days on the water.

6' wide, and a "tuna tower" like that? You are going to be picking sand out of your teeth when the first jet-ski goes by. You should put a 6' stepladder in a john boat and see how that works first.

Pat at Active Thunder would build you a 22' Active Thunder. It's just over 7' wide.
22 Banshee - Active Thunderboats

Ya, I get the no frills part. And I'm actually a fan of traditional materials when the application calls for it. But there are very basic quality levels you want to see, and an overall design that's robust. When I said quality and finish, I wasn't talking about hardware.
Ask previous owners about them, or take a close look. The price is low, and it might be fine for some.

22 x 6 is a narrow platform for fishing. At rest, it’ll be rocking around like crazy when you stand up near the gunnel, or if a 2’ wave aproaches. Narrow beam will cut through the waves better at speed but if I’m out fishing for an afternoon, I’d be wanting the stability of a wider beam.

As mentioned, there’s several 24 x 7 boats that have proven the hull design.

(Just another opinion )
RR

No Tower.