I have 56 Merc, would be better version of windshield wiper than original style

Check out New Port Engineering if you want to convert to electric wipers.

https://newportwipers.com/product/1955-56-mercury/#wiper-motor

Ditto! I have used Newport in 2 56 Fords. I would suggest adding the Adapter to use your original Wiper Knob. Extra Option.

  

I've used a Newport set up in three cars - my 48, 54 and 56 Bird.  All work very well.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I am looking for the  wiper blade I have electric wiper motor

Rock Auto sells good quality original style replacements. Not sure I understand what You are looking for? 

  

Rain-X window treatment helps greatly.  Don't even really need to use the wipers as the water beads up and rolls off improving visibility.  I use it on all my vehicles as well as headlights and outside mirrors.

1956 Ford Fairlane Town Sedan - 292 Y8 - Ford-O-Matic - 155,000 mi

you know how well the wipers blades work on my F150, I was wondering if there was a version like that would work on my 56  merc

If the existing Wipers do not work well it may be the Arms need replacing. The Spring Tension that keeps the Blades in Contact with Glass get tired over the Years.

  

What you mean electric with delay and everything?

I honestly don't know as I never saw the need for that kind of conversion due to products like Rain-X that exist.


1956 Ford Fairlane Town Sedan - 292 Y8 - Ford-O-Matic - 155,000 mi