To answer the first part. The Torque arm kit includes the correct height body mount for the rear or the sub frame. or you could have yours machined if you want them all to match.
If you have any other questions don't hesitate to call 435-628-4300
I'm also wondering which way to go. I'm going to be doing a minitub on my 69 camaro. There seems to be basically 3 different set ups. Triangulated 4 link, parallel 4 link with a panhard bar or torque arm. Is it all just preference or is one better than the rest?