I will be installing a stone tile backsplash and am wondering if
someone can give me advice about appropriate backing for the tiles.
The tiles are 6"x 6" (limestone, I believe, though I could be wrong
about that), weigh approximately 5 pounds / square foot, and the walls
are drywall painted with latex paint. Would a thinset or mastic (or
something else) be the more appropriate bonding agent to the wall? If
thinset, is there any need to back it with wire lath and a scratch/bond
coat given the weight of the tile? Also, do people have
recommendations of particular brands of thinset or mastic?

Thanks!