I'm no authority on struts, but if it were me I would get new struts and mounts front and rear. You may get by with the old mounts in the rear, but the fronts would be good to be replaced. I recently did this on mine and the ride improved a lot, more than I expected it to. Mine had clunking sounds too, but on mine it may have been due to a loose sway bar end link nut that I found after replacing the struts. Either way, when I removed the left front strut I saw that it was completely shot and leaking, the other three were not leaking but the car sat goofy with the blown strut. Check for sales on struts, I was able to save a couple hundred dollars after finding an online sale through Pep Boys, and then doing an in store pick up. The mounts I got through Jackie the Subaru parts girl on here. Locally the front strut mounts alone would have been $200 for the pair.