Species transport model of platelets and other activating factors
 

Hi guys
I am trying to incorporate a species transport model of platelets where a set of convection-diffusion-reaction equations (4 equations for each species) needs to be solved:
https://cdn.pbrd.co/images/7agfgT2Zc.png

The species that I am planning to model are shown in the following table:
https://cdn.pbrd.co/images/7ahxHmTWJ.png

And certain parameters are modeled by functions which I will have to implement using UDFs. Also there will be a boundary condition at one of the walls where fluxes for species have to be specified as functions:
https://cdn.pbrd.co/images/7akzxIiXM.png

Therefore I was wondering which approach to take, User defined scalars or the species transport model built into Fluent.

Thanks in advance.