Not sure who told you that you require a special PS pump for the SR (or even lines for that matter) but FYI… DOHC KA pumps (whether non hicas or hicas) are the exact same as the SR pumps. All you need to do is swap over the little bracket + Pulley and your done.
Now… If you have a SOHC (89-90) then the PS lines are on the wrong side of the vehicle so you either need to bend them over to the other side or get new lines made. But either way… its extremely simple so no special parts will be required.