If I were looking to purchase one off your list, it would be the 420sel. The reasoning is that the 420sel gets you the biggest body(room inside), as good of a ride as any and better than some, better gas mileage than the 560sel and almost as good as the 300sel, but with the power of a v8. I have a 90 420sel and an 89 300se. I love both. The inline six's seem for the most part have an oil consumption problem that is not really dangerous or anything, but is inconvenient on trips. The major demon of the v8's are timing chain rails/tensioners that have to be replace timely or major damage can occur ($5k). I suggest the 420sel over all on your list. Now, keep in mind as others have suggest with the age of the cars, there will be a certain amount of expense to renew the car such as rubber parts like control arm bushings, sway bar bushings, flex discs and other suspension parts like shocks. Of course, things like shocks and brakes are common with any car no matter what make. When we decide to buy another car, we will sell our 300se and buy another 420sel. If I was to go and buy another w126 knowing what I have experienced the mine so far, I would find a car with around 100k-120k for around $7k-$9k. I would have about $2k spare to have the timing chain service done, transmission service(approx. $100), check and replace all suspension parts if needed and check the blower motor/regulator for the ac/heat. A 90 420sel with that mileage will bring about $13k to the bank, so if you get for $9k and spend $2k you are still under the retail to the bank by $1k and you will be ready to ride for another 100k besides the normal services like brake pads, transmission service(every 30k-40k). I hope this helps.