Personally in 35mm format, I use a very very old Canon 50 mm macro lens, it works beautifully, and I'm sure the newer Sigma version is probably just fine and a worthwhile purchase.
I didn't have time to fully read through all of the data so I don't know if it shoots 1:1 or not but even 1:2 would probably be good enough for most people.
The most important thing is understanding light and depth of field. At the distances you're working with, you're going to have to shoot at something like f/22 or smaller of an aperture, or you'll end up with a very shallow depth and potentially out of focus areas where you wanted there to be clarity. So make sure you have some good strobes or a good off-camera flash unit if you really want to like the subject well. Of course if you have a tripod and an understanding of how your camera works where you can use the mirror up function, you can get some long exposures that will be just as good if not better than handholding with flash, and then use natural light.