Sand base or crushed limestone (pea stone) in Miami Florida?

by Ken
(Miami, Florida)

We're replacing our poured concrete walkways with an irregular shaped flagstone walkway. I've read different installation instructions and am unsure which one would be appropriate for Miami given that it rains a lot here. Should the base be 6" or 8"? I've read that putting sand in the base will wash away with the first hard rain. One article suggested stone dust or crusher-run aggregate as a base. What is this stuff? Is this the same as crushed limestone? Also, in Miami I've seen Tennessee Crab Orchard in thin, regular and thick. Some articles say 1" thick stone is OK for a walkway and others say you need at least 11/2". I would like to buy stone which is U.S. origin. Home Depot and Lowe's only seems to sell slate or sandstone from MSInternational which is imported. I went to Florida Silica & Sand in Broward County. They had Tennessee Crab Orchard and another stone called Palomino Blend. I like the idea of having a cobble stone border or crab orchard rubble strips border. Next week I'm going to Olimar Sand and Gravel. But what thickness stone should I be looking at? The walkway in front of the house is going to be about 50 feet from the driveway to the front door. The walkway in the back of the house will be about 15 feet. We have a yard with a lot of mature oak trees (and roots). We had to move the walkway closer to the house because the oak tree roots were lifting up and had cracked the concrete. The new walkway probably will receive some rain runoff from the roof eventhough we've installed a gutter. We like the keystone, but the white color really doesn't fit in with the Santa Barbara Gold irregular slate flagstone we selected for the landing near the front door. We may not do this project ourselves, but before I start to get estimates I'd like to know which stone I'm going to order as well as what the depth of the base should be and what materials it should consist of. The front of the house is shaded by the trees so there will not be any grass between the stones.