I would follow the same strategy I use with my rMBP. I use a referenced library/catalog that both Aperture and LR can access. I would never use a managed library inside an iPhoto/Apeture database package. I import the raw images from the SD or CF cards into the folder "2014" in the SSD's Pictures folder. There are subfolders for each day of the year.
After the photos are culled and edited, I use LR to move the daily subfolders to the external LaCie drives's Pictures/2014 folder. As soon as the move is done I make sure LR does a backup. As soon as LR has finished i tell Time Machine to do a backup. You can't have too many backups.
I can then tell Aperture to import the masters/originals if I want them to be seen in Aperture. Aperture is only doing a referenced library like LR, it does not copy the original/master raw files inside the Aperture database package. With the photos in Aperture I have the option of having iTunes putting some of the Aperture projects on my iPad.
I have LR put its backups on the LaCie drive. The same goes for Aperture's vault. No point taking up space on an SSD for a backup. That leaves me the max room on the SSD for the collection of new images on the the next photo trip.