Mcamera, My 818 cables are # 80238 0974W and they do fit. I am the third owner and assume these cables came with the kit. Your cables are a different format. You will have to alter cable and case to get the FFR dimensions. I would call the supplier and get the right cable format.
The ZDM transaxle cable mount kit that I have seen on fletch's car does not reverse the cable action. As stated on their web site the ($364) kit fits an MR2 shifter or a plastic Impreza shifter. facing forward.
If you reverse the Impreza shifter you may have issues with side to side lever travel. The shifter action is not symmetrical side to side. N to 1-2 is longer than N to 5-R.
Your nylon shift housing stand-offs are likely to deflect when you are shifting enthusiastically (IMO).