Digital BW, The Print

I used to be primarily a large format photographer 4x5 & 5x7, as 
well as doing a fair amount of 35mm B&W. I worked in silver and 
palladium print making. I am fairly new to digital photography and 
up to this point have only worked with digital images from my 3 
megapixel camera; I've really enjoyed it, and it has gotten me back 
into photography.  The digital darkroom is much more convienient 
than a wet darkroom, hallelujah!

In the near future I am going to get a wide format Epson printer so 
I can do B&W right, with the new B&W pigment inks.  From what I have 
been able to gather from various sources on the web for ultimate 
control and quality the way to go is using a film camera and then 
scanning the negatives.  Not desiring to pull out my old 5x7, or 
purchasing a scanner that handle it.  I will be looking at some 
second hand medium format equipment, probably 
Mamiya.  I really like the size and convienience of the 6x4.5 size 
cameras, but I haven't ruled out the possiblity of the 6x7 format.  
My question is will I see much of a difference in quality in 16x20 
size prints, between the 6x4.5 and the 6x7 format???  I plan on 
doing color as well as B&W prints.  I will probably use high 
resolution color negative films and the new higher speed B&W 
negative films that are color processed.  I may have to resort to 
processing my own higher speed B&W negatives if I can't control the 
highlights, with the other films mentioned, in my outdoor night 
photography.  I apologize for the length of this message!
Thanks to those who respond.
Randy