First thing... you need to stop putting "c last post" in your title.... People have no idea where to go when the update was ten posts ago
Just say " see page 3"
You can tell the shop that you replaced the struts and springs because the car was sagging on that side, then tell them that you are still having the sagging problem. Whether or not they find anything you still need to get an alignment after new struts, and they might just be able to find something that you can't see. Have you measured from the ground up to the wheel well? If so, and if it was not the same *on level ground* tell them that as well. You definitely don't want to go there with the 20'* on or even tell them about any problem with the larger rims and tires. They will just tell you that that is the whole problem and leave it at that.
Do you by chance have a shop in your area that sells and installs oversized rims on cars? If so, they might be able to help you out as well.