Sorbothane's products come in a vast array of shapes, sizes, and levels of squishiness, because these need to match the mass of the object you want to isolate and the vibration frequency you want to isolate from. A poor match can not only fail to help, but cause hurt.
If the goal is to be making good pictures soon, I'd suggest purchasing carefully-selected Sorbothane feet from a reliable source like Newport or Sorbothane itself (not eBay, as it would be easy to receive a counterfeit item with, say, a different durometer specification). For selecting your feet, the quick and dirty approach is to purchase feet specified so that each foot is bearing close to its recommended weight limit. Or for those inclined, a better job can be done by going to
Sorbothane's Website, downloading the Sorbothane Design Application and Design Guide pdf, and determining what you need. Edit to add:
The Sorbothane Standard Products Guide contains both useful general information and a long list of off-the-shelf isolators. Also, I have no personal experience with Sorbothane isolators, as I work in a very quiet basement.
But if the goal is to have fun along the way, by all means experiment with those squishy men. (And make sure to report your findings!

) The word "experiment" is key here, as you will probably need to spend a few hours or days figuring out what works best, if at all.
I tried plugging the little fellows into Sorbothane's calculator to see what could be seen. This is very unscientific, as I had to make a bunch of assumptions, such as the big one that the material the squishy men are made from behaves like Sorbothane elastomer. I also assumed a length of 2 inches, a width of 0.75 inches, thickness of 0.25 inches, and a durometer (measure of squishiness) of 30 (similar to gel shoe insoles). While Sorbothane's calculator allows for a number of shapes, "humanoid" is a oddly omitted. So I went with "rectangle." If this is at all predictive, Rik is quite right that a single layer of squishy men is unlikely to benefit you. In fact, it may to
amplify vibration and make things worse.
Here's a case with four squishy men supporting a 14 lb rig (yellow highlights mine):
As you can see, that system rings at 100 hz (which, I suspect, is a pretty common region for problems, and can be
heard here. Interestingly, it helps quite a bit at 200 hz or above.
But simply doubling the thickness to 0.5 inches begins to produce useful results. Notably, to get good results, you need to put a fair amount of weight on the elastomer, so spreading the squishy men widely under the bottom of your platform is probably the opposite of what you want to do. Not only is it better to have a taller elastomer column, also a more heavily loaded column.
I'd be tempted to get a bicycle inner tube of the smallest possible diameter, cut short sections out of it, stuff them cut-up bits of squishy men, and tie off the ends. I'll bet a local bike shop would happily give you a cast-off inner tube. In the calculator, a 1-inch tall, 1-inch thick cylinder works well down to about 30 hz. (To hear any frequency, plug it into an
online tone generator.)
JSP wrote: There are a few things that I'd like to achieve with lighting. I want to have my specimen lit beautifully, as if it was a professional model on vogue, to really bring out the best in it. I was taught that I should have a fill light in front, one a little to the side to bring out the depth and a light at the back "like they do to highlight the hair of a model". I've looked at photos and fiddled with lighting and I think it's absolutely true that this is what is needed, and I'd like to really try to do it well.
JSP, I photograph tiny bits of plant quite often, have similar lighting goals, and agree with you about providing in the macro studio the same degree of lighting control used in other studio photography. The lighting stage I use for this is
shown here. Like Charlie, I no longer use flash for this sort of things, as I greatly prefer being able to see how the lights play while adjusting them. Now, the articulating arms hold fiber optic light guides for a halogen illuminator. This approach is very adaptable, and keeps the heat of the lamps is far from the photographic subjects. (LEDs have improved a lot since I bought my illuminators, and the case is now pretty strong for LED lighting.)
To get the sort of images you describe, you will indeed want a combination of front light and backlight, and the ability to adjust each independently. Partial backlight is especially nice with things like fern gametes, which are thin enough to be translucent. My general workflow is to set up key lights and modifiers, then the back lights and modifiers. Then add fill light to adjust the density of the shadows. (The easier and vastly more common approach has already been described—put a light tent around your subject and flood it with broad, diffuse light.)
Pau’s advice to use cross polarization, and his examples of it early in this thread, are well worth noting. For things like fern gametes, I'd call this advice "crucial." I do not think you’ll get the sort of images you describe without using cross pol.
As has been discussed, it’s not easy to keep cut plant bits from drying out, or from moving. An approach I find helpful is to supply water to the piece of plant during the shoot, with a tiny, home-made vase of water that sits on my subject stage. Here, continuous light helps, as a plant part that is actively photosynthesizing will often take up the water nicely. And to reduce movement, one can clamp or tape down any portion of the plant that is not in the picture.
--Chris