I recommend simulating your model within SimBiology (that is, using SimBiology's ODE solvers rather than exporting your equations and solving elsewhere). This is often much faster and easier to intepret. So I personally don't see a need to use the PDE Toolbox.
In terms of what other products might be useful, the others I most commonly use are Optimization Toolbox, Global Optimization Toolbox, Statistics and Machine Learning Toolbox, and Parallel Computing Toolbox. I use the Parallel Computing Toolbox to do simulations in parallel, which is especially helpful when trying to paramererize a model. And the other toolboxes I mentioned offer useful methods for doing that parameterization.
For more information on using SimBiology, take a look at the "Get Started" section on this page.