Rooting Galaxy S2 help please

[Dx10fly]

So i want to root my Galaxy S2.
My Kernel is 2.6.35.7-I9100XWKI4.

What insecure one do i want from here, and does it matter?
[KERNEL] Insecure Kernels for use with rooting - xda-developers
Huge Download List of Insecure Kernels/Firmware to Root Samsung Galaxy S2 (SII)

If i want to go back to a secure kernel after rooting, which one do i pick from the bottom?

EDIT:
Step 6: Reload a secure kernel (optional)

Not much help when i cant find my original kernel on the internet?

EDIT2: My root is the one updated to, i guess this i want when i want to root back to a secure kernel?
Dialandroid: Install I9100XWKI4/I9100XXKI1 Android 2.3.4 Gingerbread on Galaxy S2(SII) I9100 & Changelog