Re: new shocks?
It could be any number of things, but without knowing what it sounds like it's hard to tell. I would doubt shocks, but it's possible. Most likely a worn bushing in the control arm or track bar. When I first bought my 94 Grand Cherokee it had a bad clunk in the front end. Turned out to be a loose bolt on the track bar which let things shift and bind/clunk. You might also check the endlinks on your rear sway bar. Had one break on my Cadillac and it knocked against the underbody everytime you hit a bump. My buddy had the springs on his Ebay lift kit give out and it would clunk when the suspension bottomed out on the bump stops. It also banged on the exhaust sometimes. Of course you would notice the back end of your jeep sagging badly before that happened.
As far as shocks go, I like the Old Man Emu shock on my friends WJ. They ride and handle better than the factory ones they replaced, even with a little bit of a lift. Otherwise, I've heard good things about the Bilsteins too. I don't like the Rancho RSX9000 on my ZJ. I fell for the "adjustable shock" gimic they offered. Sure they're adjustable. From "very hard" to "rattle the fillings out of your teeth hard". They handle great, especially when towing, but just ride too rough on a lightweight vehicle. Of course I'm still waiting for them to wear out or soften up a bit.