Going back and re-reading your original post, I'd tend to agree with The Real Hawkeye; a 4-inch .38 would probably by your best choice. Personally I'd opt for a S&W Model 13 simply because it offers a choice of .38 or .357 ammo. If the fixed sights are a problem then I'd consider a S&W Mod 19; again a revolver that handles both .38s and .357s. If you don't mind the extra weight (N-Frame Smiths weigh over 2 lbs.) you might want to consider a 4-inch S&W model 22 in .45 ACP; I packed one of these as a trail gun for years.
