While there are many good choices in .38 Special, the two that seem to get the most praise are the "FBI load" (158grn LSWCHP +P as loaded by Remington, Winchester, and Buffalo Bore) and Speer's 135grn +P Short Barrel Gold Dot. The Speer loading is actually designed to perform better than other loadings from short barrels, not just to be more pleasant. If you look at the bullet of the Speer, you'll notice that it has a much larger hollowpoint cavity, this is to facilitate expansion even at relatively low velocities. While both the Speer and FBI loadings are excellent, if you're using a lightweight gun I think I might gravitate a bit more towards the Speer as jacketed bullets seem to resist jumping crimp more than lead ones do.
In .357 Magnum, it depends a lot on the shooter. Even from a short barrel, you can get very impressive ballistics from a .357 Magnum but it comes at the price of recoil, which can be excessive in small revolvers. From a purely ballistics standpoint, magnum loadings with bullets of 140 grn and heavier are best as they tend to lose less velocity from short barrels than their lighter, faster counterparts. Cor-Bon 140grn JHP, Winchester 145grn Silvertips, and the 158grn SJHP loadings from Winchester, Remington, and Federal are all good short barrel performers in .357 Magnum. If recoil is an issue, you might be better off using one of the "mid-range" or "medium velocity" .357 Magnum loadings. Good choices in this category include Remington's 125grn Golden Saber, Speer's 135grn Short Barrel Gold Dot (this loading is quite mild and really isn't all that much faster than the .38 +P SBGD), and the various 110grn SJHP loadings from Winchester, Remington, and Federal.
As far as ejecting shorter cases, Ruger SP101's and Colt snubbies have a longer ejector rod than short barreled S&W's. This is because S&W's lock at the end of the ejector rod while newer Rugers (the old Security, Speed, and Police Service Six's locked up like a S&W) and Colts do not. Thusly, Rugers and Colts don't have to have the locking mechanism and can have a longer rod. Even so, I've never found a short ejector rod to be an issue so long as proper reloading technique (point the revolver straight up and give the ejector rod a sharp rap).