One powder for .357? BlueDot, all my most accurate loads have been with this. 2 powders? Blue Dot and Unique as the latter has lot's of versatility. 3 powders? BlueDot, Unique and TiteGroup. Have great luck with Titegroup in lightish small game loads but if you load it anywhere on the high side it tends to melt the base of cast bullets and cause leading.
For bullets I use some commercial 158gr hardcast lead and Berry's plated 158gr. FPs for plinkiin/small game. For anything serious I've settled on Hornady XTP's in 158 and 180 gr.