I had RHD Japan list the harness and also asked Jesse Streeter a little while ago about them.
I only hear last year that they were a discontinued item, but RHD & Jesse both buy them directly from HKS.
iS is superior to the eManage Ultimate as it can handle the variable valve timing without an add-on unit.
Also has a video out to display 6 options from a number of readouts (oil pressure, boost, temps etc) - perfect for those with an OEM popup screen... like me
Would be looking at either a 3.24 or 3.3 only, nothing earlier than that for the V-Pro.