The .357 Magnum is a good round, I prefer the 125 grain jacketed hollow point +P version myself, Federal makes a
nice one.
Despite having one as a duty weapon (it was a 686 Distinguished Combat Magum 4") I prefer to avoid the S&W weapons.
Ruger makes a number of very fine .357 Magnum revolvers. I prefer them as well as a good Colt.
In the proper holster, a 4" is as easily concealed as a 2", and far more useful.
While revolvers are inherently more accurate than self shuckers, a good self shucker is plenty accurate for personal defense.
All things considered, a revolver is also inherently more reliable than a self shucker of the same quality. Fewer moving parts performing fewer functions and operations.
Self shuckers are also easier to carry concealed, since they are flat, slab sided, and shorter, given the same barrel length.
HOWEVER, I STRONGLY suggest you avoid single action self shuckers such as the vaunted legendary Colt 1911 pattern. Do not get me wrong, I LOVE those guns. But they must be COCKED before they will fire, and confronting ANYONE with a cocked single action weapon leaves you VERY vulnerable to all sorts of criminal and civil actions. Carrying a single action self shucker is best left to seriously dedicated personnel. It (the 1911 pattern weapon)was never designed or intended to be used in a civilian environment. It was specifically designed to kill large numbers of ENEMY SOLDIERS as quickly and efficiently as possible. It does that well. But it is NOT the weapon for the inexperienced nervous civilian AKA the NDP (Non Dedicated Personnel).]
The Para Ordnance LDA is available in several versions for personal defence, and it is VERY good for that job. It combines the near divine perfection that John Moses Browning achieved when he gave us the Colt 1911, with the double action safety of the modern weapons world.
With a 45 ACP, the 230 grain jacketed hollow cavity is the best round, CCI-Speer is the most popular.
The secret to concealed carry for personal defense is to get the right weapon/holster combination for the INDIVIDUAL, and extensive practice and training. Find the weapon that best suits the inividual (the prerequisite being that it can be carried and concealed on the person carrying), and then find the holster that conceals it well but makes it available. Then train, and practice. If you are not willing to practice the draw and firing at leastonce a month, you probably should not carry. And do not forget to have a skilled gunsmith tune ANY weapon you purchase for personal defence. Do not be fooled by the Bravo Sierra, a good personal defence tune up INCLUDING a PERSONAL DEFENCE action job will NOT make you subject to more criminal or civil liabilities. The key being the action job done with personal defence in mind and not a target trigger action job.
Carrying concealed is exercising a right as a citizen that carries great responsibility and duty as a person and a citizen. Approach it in that manner and everything will work out as well as possible.
I hope that helps, and good luck to your brother.