Many late GM whels have the dimensions cast into the back face. For a 7" wide rim you want a 46 mm offset. GM FWD rims com in 5x100mm (smaller cars) and 5x115mm (larger cars). Chrysler wheels 5x4.5" which comes out to 5x114.3 mm are said to fit but I prefer the right ones. The wheels in the first post look like 1993 wheels which were available in silver on SLE Bonnevilles. They are usually referred to as crosslaced wheels.
Aftermarket wheels often come in dual patterns so 5x100 and 5x115 are often on the same wheel.
Ofset is important - the more it has, the further in the centerline of the wheel sits. As I said, a stock GM wheel FWD 7" wheel has a 46 mm offest. Many aftermarket wheels are 38 mm which means the wheel sticks out about 1/2" further. Too low an offset can upset the steering geometry and rub the wheel well at full lock . Too high and you can have clearance problems on the struts.
Just to add to the mixture some use backspacing instead of offset and reeally confuse things. This is why I tend to stick to GM factory wheels. They are all measured the same way.
Below is the 1990 Bonneville grey 16x7 wheel (available on SE, SSE was gold). It is actually three pieces - the wheel, the center cover, and the plastic "lug nut" that holds the center on. I recently replaced all four of the black plastic centers because the originals were full of cracks.