I've got 4 Manga series.  Here are the sizes:

Dragonball, Ranma :  4.5 by 7 inches
3X3 Eyes          :  5   by 7 inches
Maison Ikkoku     :  6   by 8.3 inches

The Maison Ikkoku is the Wide Edition or wide-ban AFAIK.  The Ramna and Dr
Dragonball are normal size for most, while I guess the 3x3 Eyes is
mid-sized.  The paper for Maison Ikkoku is very white, while the others
remind me of newsprint quality.  The cover jacket is much nicer for
Maison too.  Each Maison has two color plates in them.

If Ranma ever does come out in a wide-ban, I know I'll be getting them.

The viz GN's measure 5.5 by 8 inches by the by.

My understanding is it takes 1-2 years for a series to go wide-ban
after it completes.  So it still might be awhile.  But I'd rather
give an option to others before they spend their money.

-wayne-