Rear Trailing arm

Here is the meat and potatoes to this whole adventure.
I plan on using the 3si rear trailing arm so I can:
-Retain an ebrake
-Run Larger vented rotors
-Bolt up 3si, or evo 8 calipers WITHOUT brackets.

(I don't believe there is any rear brake upgrade for our cars that will allow you to retain the e-brake)

Differences:
-Shock mount distance from centre is longer. This will actually lower the car.
-Shock mount is thicker. BUT in my one picture you can see that mitsu just welded a piece of metal dowel overtop of another dowel. I am hoping to cut the dowel off and the mount underneath will be the same size as the dsm one! TBD
-Width, you can clearly see an inch, if not more difference in width.
-Internal e-brake obviously. E-brake cable capability TBD.
-Balljoints. Now there are a couple ways to make this work. It seems ALL the fastening hardware is larger on the 3si stuff. subframe mounting bolts, and balljoints. I could have either:
-used the 3si control arms, and had a sleeve pressed into the subframe mounting side for the smaller DSM bolt.
-Used the 3si control arms, drill out the dsm subframe for a larger bolt that the 3si uses.
-Press out the 3si balljoint, and press it into the DSM lower arm.

I chose the last option. ***But NOTE*** through my searching there is no oem balljoint available for the 3si. You need to purchase the arm. ($300) OR use a joint from an 80's dodge D50 and use ring shims to make up the larger gap for the snap ring groove. (not a huge deal)

Luckily with my adjustable camber arms the upper balljoint shank flares out enough to work with the upper trailing arm mounting point.