I guess it comes down to the type of vegetables you use and how you want them cut. I use gyuto most of the time because I can push cut, slice, chop and have pointed tip for fine work. I use an usuba for katsuramuki(paper thin vegetable sheet) and finely cut with gyuto for garnish.
Here is an example - Link to Pic: kamagata-usuba-t1641.html
I also use small petty for garnish work with carrot, cucumber, daikon, radish, citrus fruits, onion, etc.
Not a fan of cleavers, I don't use nakiri either. A gyuto does almost all vegetable tasks for me.
I do not own a sujihiki. I would like one of course, however I currently cannot justify purchasing one. The ingredients I use daily and how they need to be cut; would not be any easier to prep with sujihiki than with a gyuto.
Also, as far as length goes, again it all depends on what you cut and how you want to cut it. For example, if you work over
the cutting board, knuckle clearence and maximum length can play a role in what knife to use. For some who work in front
of the board (hands hover and only the blade reaches the board); length determines how far from the board you have to stand. You may find there is no maximum length working in front of the board.(although you might never use the heel of the knife)
Gyuto handles everything I throw at it. It's a thin profile, like ~2.4mm and wedges hardly at all.
Don't let me deter you from finding a knife you love because I don't have a need for it, you may find a style that is more fit for you. I would recommend a small petty it's great for messing about.