15 inch wheels were a standard on the w202s.
16 inch rims are fine to, so long as you maintain the similar overall diameter rolling radius of the installed wheel/tire combination to that of the oem, as well maintain the same/similar ET (offset) of the oem wheels.
Look into your owner's manual to review the oem wheel tire size combination. You can even go up to 17inch (or even 18 inch).
Also do search on the forum here as many have gone to 16, 17 and 18inches without required suspension modifications.

 

205-55/16 was a stock size for your car.

 

Any specific recommendations on rim type (manufacturer, etc)? Would it be best for me to obtain a set of OEM 16" rims off a C280 Sport model?

 

That is safest if you want the correct offset.

 

I got 17" rims. That's as low-pro as I would go if you still want the car to be decently comfortable.

 

I have 18" wheels, 8" wide front 215/40 tyre, 9,5" wide rear with 245/35 tyre. Both are offset 35. They are not uncomfortable but since they are big they weigh alot and that is a slight negative on the driving experience. Feels quite responsive tho.

These dimensions are in my mind the maximum you would want to go to, since going wider would bring fitment issues and going to 19" or more would require tyre so thin it would become uncomfortable.

17" or 16" with stock offset of 37 or 35 will work just fine, just keep in mind that if you make the rear offset the same as front, the rears are going to sit deeper in the wheelwell and look funky, like they do in stock form. I would put 1" wider rims in the back or put an offset of 20 wheel in there.