The Smith & Wesson "N" Frames guns are the M-28 (the old Highway Patrolman in 357, now discontinued)
The M-27 (which is almost the same gun but in a nicer finish)
the M-24 which is a 44 Special, (discontinued too I think)
the M-25 and 25-5 in both 45 ACP and 45 Colt,
the M-57 in 41 magnum with fine finish and adjustable sights,
the M58 which is a 41 magnum with fixed rear sight (actually a groove in the top strap. also discontinued)
and the M-29 which is a 44 Magnum.
All the above guns have the same size frame.
In "something comparable" you have the Ruger GP100 in 357 and the Ruger Red hawk in 44 magnum.
Taurus offers a few large frame revolvers too, but you hear mixed reviews on their quality.
I would recommend that you load your own ammo no matter what choice you make. When you load your own a whole new world is open to you in verticality and cost savings.
Any of the calibers offered here is fine with the 357 being the least expensive to make ammo for (you can load 38 specials and shoot them in the 357) and the 45 ACP being fairly cheep too.
The 44 Magnum is the most vertical of the lot when it comes to covering the most bases in one caliber, but that is only true if you load your own. However the bigger the bullet the more lead it takes to make a bullet. The 44s and 45s cost the most for the bullets, and if you load on the powerful end of the scale, the charges of powder in the 18 to 24 grain range will eat up money faster than charges in the 4-5 grain range like you can use in the 38 special and the 45 ACP.
Bigger shells like the 41, 44s and 45 Colt can use low powder weights and save you money in that way, but they still use heavier bullets than the 38/357 guns.
So the real issue is to define your “mission statement” for the handgun you buy. If you will never use it for anything larger than a deer the 357 magnum is likely to be your best choice. The 44 magnum can be down loaded a great deal, and make it cover the same bases as the 38 or 357, and do it as well or better, but it begs the question;
Is that truly a concern? Only you can answer that question for yourself. Such guns are usually lifetime investments.
If you load your own ammo I am sure you will be happy with any caliber you choose. Bigger is usually “better” in the ability to cover more ground from mild to powerful loads, but the very high end of handgun performance is largely unneeded for most shooters.