Laying out ListCtrl objects in sizers?

Hi all,
I don't know if I've said, but I'm using a screen reader, because I'm
visually impaired. To me, my app looks great--everything is picked up
by the screen reader, and the tab key moves me to all my controls.
Visually, though, I think it needs some help.

I'm using a GridBagSizer, because that seemed the easiest. I'm using a
BagSizer over a standard GridSizer because I have a couple ListCtrl
objects which have several columns, so I wanted the "span" option. So
far, though, I haven't seen any examples take this approach, and I'm
starting to wonder if I need to. I just don't want to cut off columns,
and I want a good number of rows to show at once. I also have "add",
"edit", and "delete" buttons I want below the list, and in one case,
"start" and "stop" buttons to its right. On one tab, I have a second
list that should be to the right of the first. I only hesitate to use
box sizers because, as I said, I want to have the lists be big enough
to be useful. I also don't want my buttons to be huge.

Obviously, laying this all out without being able to see it is a bit
of a challenge. I seem to recall asking about this years back, but
that was for a very different application. So, what do you all suggest
as a way to get a decent layout, but without my list being squeezed
way down or my buttons being blown way up?

Post a visual image of what you want. Maybe use mspaint or something.