That looks really good so far, can't wait to see the finished product! Are you going to be boxing the rear frame at all? I also see the pieces of angle iron you are using in the rear to keep the frame off the ground I assume, how did you go about making sure the frame was square before you began cutting?
I am planning on boxing the rear frame of my sy soon and adding the ridetech rear 4-link. I like your idea of using the angle iron to help support it as its quick and easy to do and I won't have to waste a bunch of jack stands to keep it supported!
Good luck with the project its looking really good