All,
I would like to start out by saying Hello as this is my first time owning a Toyota and posting to TN. I own a 2000 Camry LE Automatic with Cruise Control, I believe that means I have a 5fse engine, but the cruise control may change that. I used to own a 1992 Saturn SL2, which was a real beater

, anyway I have done a couple repairs: Serpentine Belt, and the Lower Left Control Arm on that car, but otherwise I am pretty new at this stuff, hence DIY_
Apprentice so please recognize this if you wish to help. I would love to learn more.
My questions are as follows:
I love everything about my car except that there is a loud clunking noise in the rear of the vehicle everytime I go over a sizable bump or hole, or when I turn sharply. Now I have read probably every Gen 4 Suspension Post on TN, so I know it could be bushings, struts, rsb, etc. and have also read that replacing the rsb and rear suspension may be just what is needed, however everyone suggests TRD or Whiteline, my question is if I don't necessarily want the car for "performance" but for good handling and smooth ride, what parts should I replace and what parts would be suggested?
Second, I live in MN where it gets -40 in winter occasionally and there is salt salt everywhere, are there any mods/upgrades that I could do to decrease the impact of driving in winter?
Lastly, what is the best oil for my vehicle, and why do you think so.
Disclaimer: please be specific and could someone explain to me what the difference between struts, springs, shocks, etc. is.
I know this is an exceptionally long post, but any help would be greatly appreciated. Thanks.
FYI: 65,000 Miles, Car's original home: Arizona, Budget: $1500.