I want to use the following type multi select layout for a choice control if possible. I only seem to be able to use it in a lookup control. The Choice control only seems to allow check boxes. but what if I have 1000 checkboxes. doesn't really work.
Its just not an out of the box feature unfortunately. That's probably not what you'd like to hear, but true. Why this format isn't available in the choice is beyond me, but it sure does seem like something that should be posted in User Voice. Who knows maybe they'll add it in the future.
I personally would like to see a "list" style multi-select with checkboxes (opposed to having ctrl or shift click) when using the list format.
My personal choice would be to use a lookup list if there're more than 10-25 choice items to select from... Certainly with 1000(+) items. Which would than give you access to the mention control (or its list version).