Could be a handful of things. And I hate to tell you, but checking them involves you laying on the ground under the car in that cold weather.
The sway bar links are in the rear, so your noise coming from the front tells me you are probably right in that guess.
The common thing is the braking support ball joint to make noise under there. it is connected to the lower control arm, and mounts to the body under the footwells of the driver and passenger. They can klunk when you go over bumps. If the boot is gone protecting the ball joint, the joint usually goes soon after. Dirt is no friend to this guy.
Then start poking around underneath, grabbing at the steering components. It will take some effort to flex them but try to move the tie rod ends and drag link bushings around. push them in and out, to try to compress the ball inside. (I hope I am explaining this ok) You will have to really hang on them to move them. The weight of the car moves them otherwise, so an average size person is not much load.
You might try to flex the ball joints somehow, this is tough.
Look at the top of the shocks, when you move the car up and down. Do the bushings ever lose contact with the mount? As if the nut was not tight enough to compress the bushing. Then check the bottom mount also. Shocks last a long time on these cars, so the bushings drying up is not unusual. I have no idea where to get new ones without the shocks though!
I hope I gave you some ideas. Search by my name, as I fought this with my 560SEL for a bit. I posted all the things I repaired.
1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)