For galvanized, use Simpson hardware. The labels will indicate the hot dipped saddles. The through bolts and washers/nuts all have to be galvanized too. Same goes for any lag bolts. members not exposed to driven water or snow can be fastened with deck screws or galvanized nails.
I have also gone to extremes with stainless steel screws but they are really expensive.
How about a sketch of your project? Scan it as a jpeg and post the sucker!