S&W has been making their alum. frame models for decades. As long as you use a little common sense you will be fine. I wouldn't recommend a serious and constant amount of practice with +P ammo for example (use a steel frame back-up gun for that). I would have no reservations using an ultra-light gun for carry purposes.
As far as guns I'd prefer an 850 in aluminum but I don't think Taurus makes that combo (its in Ti but why spend the $$$). The other choice would be an 851, which does come in aluminum. Regardless I'd want stainless to help prevent rust from your sweat and body oils. Both of these models have covered hammers to ease the draw from the pocket (hammer spurs can catch). The 851 will tend (from what I've heard) to collect lint in the hammer area but its not a big deal.
The other, old school, option would be to get an M85UL (in stainless I'd hope) and remove the hammer spur (unless you can find a used one with the factory spurless hammer). You can do it with a dremel at home. It will work but will be a little ugly (I know mine is) or you could have a smith do it and have it prettier. I have never had any ignition issues with mine, even with stuff that supposedly had hard primers (S&B and I have some Blazer downstairs I will be using at some point).
Now if you want a bit more punch there is the 651SC or the 605 SH. Now I will say that these WILL be a handful with magnums. I do not recommend using magnums for carry until you have had much pain/practice on the range.
You could use a steel framed gun but it won't carry as nice (but will be easier to shoot).
Another note. Once I had a chance to try a Taurus small frame 38 UL (I think it was a M85). It felt like a steel frame 357 (think M605). That is where I first got the idea that the factory 2 finger grip wasn't for me. The 3 finger is much better, but there is a loss of concealability with the longer grip. The main difference is in the material of the grip. The 2 finger is plastic-like and the 3 finger is rubber.
A book I highly recommend is The Snubby Revolver by Ed Lovette. I'm currently without a copy as I lent it out. The initial price of the but is cheap but the price goes up quickly after you read it. The increase is about the cost of a snubbie revolver.... I know mine was.
Some people will carry 2 small frame guns, one in each front pocket. It gives you the option to use you off hand to shoot if your primary is "occupied" and it gives you a much faster reload if one is needed. If I were to take this route I would carry a steel framed gun for my left hand as I don't have the recoil tolerance there.
Had mine for 10 years, accurate, rugged, +P compatible. I love the thing. It's a stainless M85UL. For pocket carry, I'd suggest a concealed hammer model, but I carry mine pocket with no problems. The hammerless is just a little more snag resistant.
put about 200 rounds of about every cheap +p I could run through a 85ul- no problems, no misfires, and accurate with the cheap ammo. I carry it in a fobus paddle holster. I would recommend it to anyone and everyone.
Yes very dependable. The only thing to watch for is a "half trigger pull" followed by letting up on the trigger. This will leave the cylinder stop (the thing on the bottom that catches the cylinder notches) in between notches. If you re-holster the gun - the next time you draw, it may lock up. So when you holster the weapon make sure the stop is fully engaged in a notch. Not a big deal, but some to watch for.