I don't know about the VTI/EJ9, but if you have a stock front sway bar that will be fine, no need to go larger as larger front bars promote more understeer, understeer is your enemy. Paired with the EK9 rear bar, any front sway bar is suitable but a larger bar like the EK9's will give more understeer and less front roll, a smaller factory front bar will promote turn in and give less understeer.
As explained here http://www.ek9.org/forum/suspension/31-information-about-ek-sway-bars-usefull-information.html there are two options for running the front sway bar, the EK9/EK4 front arms+forks and the -insert UKDM sway bar equipped ek's- front arms. Also explained in that thread is that the EK9 LCA is thicker at the shock fork, making the shock forks different than what you have.
Ahhh thanks mate
Thats a handy thread. I better get reading.
My car standard doesnt have Sway bars, nor do i have the holes to fit one
I was just planning on a EK9 sway bar set up since EK9's are known for thier very good handling