What about this 4eat?
 

Now I have come across a wrecked 1998 Forester with an automatic transmission. I know its the OBD2 system and my 1994 is the OBD1. Im pretty sure the 98 forester came with a 4eat auto. How do I get this to work in my SVX? And is it a better 4eat or am I running into the same problematic auto? Will the Forester torque converter work?

I can also get the rear diff from the same car. I am unsure of the gear ratio.
I am very mechanically inclined. I was raised in my families auto garage and worked there until I moved out to start my own life. I can even fab and modify. I can also fab up wiring cables and such.

I'm just wondering if this is all going to be worth it and what issues I am going to run into and how to get over those hurdles?

IIRC '98 is around the cutoff year(s) for a bolt in. Look at the tranny, for a spin on fluid filter. If it has this, it won't fit.