[What rear suspension should I swap into my first gen Brat.]

What rear suspension should I swap into my 1981 brat. Fabrication is not a problem.  I plan on swapping in a ej22 later. A better question would be, what donor car should I be looking for. Years and models please. Im new to subarus. Id also like to keep the D/R 4spd. Unless i can find a better D/R option.

[New to the message board. Looking for information on my brat, and part interchangeably.]

Looking to find out what parts car i need for rear suspension and ej 22 swap into my 1981 brat. I know the later subarus are a little wider. But there's not much room for lift or maint. Parts for the first gen rear. What parts car should I be looking for  to get the parts i need? 85-98 impreza? 86-98 legacy? Baja? Please help. Im an experienced fabrcator and car builder with a great shop, money and time. Im just new to subarus.