You can spend a lot of money trying to solve noise, when often you can eliminate certain areas early on.
This is where is gets scary.
For me, since I've done this for years, I would jack up the pumpkin, place 4X8 chunks (or 4X6) under the rear tyres and set it down.
This sets the position of the suspension as it would be in use.
Chock the front tyres, both sides, front and rear.
Engine off, keys in pocket, park brake off, in neutral.
I cannot recall the specifics off the top of my head on support on rear suspension, but, you might be able to support the car if you can get the jackstands out far enough to hold the suspension in a position normal for on-the-ground.
Mechanical advantage and leverage sometimes means that if you support the car inside of the center line of the whels, the suspension will try to unload, the control arms will [censored] to an angle, and the car will try to exit it's position upon said jackstands.
If you are unsure of you chocking skills, might be handy to have an assistant sit in the driver's seat to hit the brakes if needed.
Slide under back of car, grab half-shafts and check for rotational play, and up/down play.
I have been known to use a long, fat screwdriver or prybar to force rotation, looking for movement and LISTENING for noise.
Your joints have grease zerks?
Ever grease them?
Slip-shaft?
Then, check the companion flange at the sides of the pumpkin.
Been a lot of years, but if I recall, the u-joint assembly sandwiches the brake rotor to the diff companion flange, and slight prising on the disc to see if it wobbles will tell.
Check the main shaft u-joints next, same procedure, same greasing.
Then, jack it back up, check your wheel bearings and hubs for ply, noise, runout.
A good way to check for noise is actually by touch.
With car blocked on stands, slide under, touch the carrier, with you hand and fingers fully clear of any contact with rotating parts.
Have an assistant spin the wheel.
You have a bad bearing, you will feel it in your fingertips.
With radio, a/c, all that off, windows down, car on the ground, start it up.
Automatic?
Brakes on, shift to reverse while listening carefully.
Hear any "clink" noise?
Shift to drive while listening.
Hear any "clink" noise?
"Clink" is often the sign of loose u-joints.
When the slack runs out of the needles and cross shaft, the impact noise is transmitted to the hollow driveshafts, hence the "clink".
I have heard tyres make the noise, but generally heavy tread all-weather tyres.
Stacking noise suppressing material in the boot with no effect more indicates a mechanical issue, but, you never know.
If you don't hear the noise from the front, you can rotate tyres front to back and see if it changes.
Now, if you had a flatbed hoist (like a muffler shop uses), or an old-fashioned grease pit, you could just drive up on it and no jacking.