Strongly verbal thinker here: weak "mind's eye" (or nose, or ear). I can remember and later identify images, music, etc with a high degree of accuracy, but when I call something up for "internal recall" my memory will almost always lack the fine detail of reality. It's very rare that I can "play back" or "conjure up" something in my head vividly. I don't absolutely require an internal monologue to think. With some things, like sports or gaming, there's a lot of non-verbal processing going on.
I can do reasonably complex verbal, mathematical, or IT work just in my head, and often have an internal monologue running while doing so. It not that my working memory[1] is especially good, it's just that if I'm spending more than a couple hours on it, I've mostly memorized it, so I can think about the solution, or at least the next step or steps, and then type or write them out. (Closing my eyes can help eliminate distractions, but isn't required. Good headphones playing something non-intrusive and blocking out audible distractions are at least as important, probably more important.)
What I can't do in my head is solve complex problems in real 3D space. If I'm trying to fit components into a box for a hobby project, or doing some moderately complicated carpentry for a home-improvement project, I prefer being hands-on. Need to be hands-on, really. I can't fit the pieces together in my head, even if I'm looking at a page full of all relevant measurements. 3D modeling software is okay, pencil and paper and drawing tools a very poor and painful substitute.
Interestingly, when I'm working with a hands-on project is one of the few times when I can make a very sharp mental picture. I can be looking at a piece of lumber, or a bare enclosure, and know it exactly what it will look like when I'm done.
