I just spent two weeks in San Pedro chasing bones with the fly. The fish down there are not the big boys you'd find at other places around the world. 1-3 pound bones are what you'll be chasing so you can go with lighter line which will help you cast smaller offerings. 8 lb would be the heaviest I would use, 6 being a better choice for the bones. Tie some small white jigs with maybe a bit of orange in them. The fish I caught over grassy bottoms liked something greenish or a darker tan and when I was fishing over sand the patterns needed to be very light in color. White with a bit of copper. Learn how to tie on a shock tippet for the tarpon or you won't be fighting them very long.

I caught snook and tarpon also but that required the use of a boat which I did have access to.
You could email me if you've never been there before and I can give you an idea of what to expect in that wonderful little town.
The guide that I know down there fishes quite a bit with spinning gear so I could give you his contact info. It would be money well spent going with a guide early in your vaction.
Dave