I would suggest ST185 GR2 in the back. Why?
-Shorter strut, more travel allowed when lowered.
-Cheap
-Typically you want a hard front, softer rear, depending on your driving style
The first thing that I noticed on my TEIN setup, was that the rear shock was much shorter. I'd try to duplicate this. When you put long front struts in the back, you are almost out of travel when the car is lowered.
On the flip side, the OEM rear shocks are actually longer then the front. The longer shock, when at stock height, allows the car to soak up dips and bumps in the road without a harsh ride.