Shocks-
With the leaf springs located and installed, I was able to measure for shocks. I went with a set of Monroe 5752 - 4'' travel, 8.625'' compressed. Their vehicle application is a similar weight range to a loaded trailer and they have relatively appropriate dimensions. I ziptied the shock in a mid position and split the travel 60/40, biased towards more uptravel. I loaded up the trailer to compress the leaf springs into a more realistic driving position. The trailer frame doesn't have a great option for upper shock mounts, so I fabricated a cross bar from a piece of 2x2x1/8 angle, and had to cut out some windows for the pop up lifting cables. I gusseted the shock mount locations and the cutout windows to help resist the twist. I tacked the upper shock tabs in the highest position I could to the crossbar, and offset them as close to the leaf spring as I could leaving some clearance to get the welder in there for the lower tabs. Then I bolted up the ziptied shock, bolted the lower shock tabs to the shock, and was able to play with the crossbar location, sliding it closer/further from the axle. I chose a position between a vertical shock and having the lower tabs protrude below the axle pad.