Tranny noise -- part X

[Joe Yakubik <75363.2524@compuserve.com>]

Semi-longtime readers may remember I asked about noisy trannies a while back.
To bring you up to date: the suspected leak was caused by the power steering
reservoir dripping onto the tranny - easy fix.  The meister at the Audi dealer
(who, BTW, was wearing lederhosen and a blue VW-Audi lab coat) said the noise
was somewhere in the drivetrain/transmission but couldn't say where.  He did
offer to dismantle, "repair" and re-assemble the tranny for the bargain price of
4500 DM (approx $3000).  He then topped off the tranny fluid with approx
one-half liter oil (coincidentally the difference in the Bentley from  "normal"
to "full") for free and wished me luck.  Then, John Winkelman described similar
symptoms caused by a bad U-joint - back to the lift.  A different technician
then showed me that yes, the U-joint/driveshaft was going bad, but that my
problem was more likely the motor mounts, which are also going bad.  I tend to
agree with this.
Car: 91 200 TQW (20v)  US spec.  Almost 60k miles.  Stock.
Symptoms:  Roaring/grinding noise that is apparently torque dependent.  Earlier
heard only in first and second gears, now also in third, fourth, and sometimes
fifth under hard acceleration.  Slight "kick" in the shifter with abrupt clutch
usage (not popping the clutch, just not always smooth).  No significant shifting
problems, but subjectively not as smooth as earlier.
Suspected cause: Slack in the drivetrain caused by deteriorating motor mounts
and U-joint.
Projected fix:  Replace the motor mounts and maybe the drive-shaft ($$$ and
effort dependent, per Bentley U-joint/driveshaft is one piece).
Questions:  The Bentley manual describes swapping the motor, but is not real
clear on just the mounts.  Is this possible/complicated/better left to the pros?
Am I kidding myself about the tranny rebuild? Is there anything else I should do
while under the car?  Any upgrades to the mounts, polyurethane too stiff, maybe?
Any other advice, hints, suggestions, $ and time estimates?  I have access to a
hydraulic lift and a basic auto workshop minus Audi specific tools.

Joe Yakubik