Difference between Alloderm and Strattice?

Alloderm is human skin and hence is defined as an allograft.  Xenografts are grafts from non humans such as the pig (porcine).  Strattice is a porcine graft and hence is a xenograft.  Both work in the human because of the processing by the company which removes antigens that cause rejection.  Both are well accepted in human surgery and have many millions of uses in man.  The choice in using them is related often to the surgeons preference.  Alloderm is softer and easier to sew through.  Strattice is typically thicker and tougher and sometimes preferable because of the thickness and strength it provides.  

Your surgeon has the capability to perform the bottom out support procedure with several acellular dermal matrix products (ADMs). You can have a procedure that respects your wishes and allows a successful procedure.
The Strattice is porcine or pig skin acellular dermal matrix. It has no antigenicity, and has been shown to have almost no immune response. Strattice is substantially cheaper and has somewhat higher tensile strength. But in a bottom out surgery, the thick or extra thick Alloderm pieces can provide the appropriate reinforcement of your stretched out fold.  
I know the technical profiles of a host of other dermal matrix products, but none that have the science and process specifics of Alloderm. Alloderm safety profile is the most studied. All other products compare themselves to Alloderm in one way or another.

many surgeons use adm for a variety of problems including the one you are having.  non-porcine adms are available and if this is your preference, it should not alter your final result.  

The main difference between these two products as you have already noted is in the origin: porcine vs. human cadaveric. They are both produced by the same manufacturers and work in a similar fashion. The primary reason Strattic has become the go-to product for revisionary cosmetic procedures is that of cost. Strattice is less costly than Alloderm. In the comsetic setting, where insurance is not involved and the patient bears the brunt of cost, Strattice is the more economical choice.Ultimately, both are safe and effective options for the treatment of "bottoming out." If the idea of using a product of porcine origin is of concern there are a number of other ADM options available from other manufacturers which may offer some cost savings over Alloderm. Alternatively, you could choose to pay for the additional cost of Alloderm.As always, discuss your concerns with a board certified plastic surgeon.

Both Strattice and Alloderm are great products. The strattice is a little more firm but sometimes that is desirable in trying to maintain the position of the implant and revise a pocket. I use it in the cosmetic setting for what you are describing b/c of its strength and b/c it is less expensive. In the process of treating the pig skin all protein is removed so that your body doesn't "reject" it. Basically it is a sterile scaffolding or matrix that your body infiltrates with your own blood vessels and building blocks. That said, if your more comfortable with Alloderm then I would use that. Best of Luck!