Re: 03 cobra w/solid axle/gear
It sounds like you have a really good plan and know exactly what you want. The TLOC, 31-spline Moser's and a fresh set of bearings will probably get rid of your problem right away. At that point, you've literally replaced all of the components that could be causing your issue.
Make sure to go with the full installation kit that includes side carrier bearings, pinion bearing, pinion nut, crush collar, etc. Also, make sure that you use the correct weight non-synthetic gear oil for the TLOK and you'll be in great shape!
Out of curiosity, have you installed aftermarket IRS bushings or anything that could be causing the clunk / worn out?