ZDriver.com - 87 Z31 Have a couple Questions

Hello everyone my name is Michael and I am now the owner of a beautiful white Z31 who needs some love, I hear the differential mount is the main problem, I'm trash so I drive Auto but shifting causes a very noticeable "bump" but only when changing from park to reverse or reverse to neutral or neutral to drive then after you get to drive changing between 1, 2, and drive doesn't do anything. I also need a rear windshield replaced and a new passenger mirror, I could look online like most people or pony up like 500$ and take it to a glass shop but I'm curious as to what the community has to say. Other than that the drive is for the most part smooth, it shifts perfectly but it feels like the rear end definitely has problems. I plan on putting a lot of love and such into this car but these are the main problems. I am also from southern Oregon. Also any recommendations for what rims and such you would suggest would be awesome, I was looking at black and whit Motegis. Any help is appreciated. Car is Non turbo and completely stock no backseats either.