I remember that there was a SVT rear suspension (with the crossmember) at a Texas junkyard for ~$200. I was going to buy it when I went to the national meet, but since I didn't go... Anyway, I found it on car-part. It looks like it has been sold, but there are others now. Just look for 'w/crossmember (assm), disc rear brakes (2.5L), SVT'
I was going to do it this way so I could get everything done then unbolt my subframe and slide the new one under. That way there would be less downtime, especially if I ran into a problem.