These are out of a 200 sport , they look tidy enough from the pics , I'd imagine Merc ones are huge and the tombstone Porsche look seat does nothing for me ...as would the price Id imagine .
I don't like L200 seats, they have a very flat, hard base with no real leg support. My friend has an L200 and any time we do a journey longer than 1hr I feel wrecked after getting out of it!
I suppose if you mounted the base at more of an angle backwards it would help support the legs.
I stripped down a pair of Granada Scorpio V6 electric seats for one of my projects and the base is quite compact. You can get the Scorpio in leather too and there are plenty of them around. The upholstery ones look dated and would need recovering to look more modern. Foam is comfortable and they are also heated with lumbar support too.
Here's a stripped down seat to give you an idea.
You could also look at Mazda MX5 or Honda S2000...but they are fairly similar in shape to the 944 above.