You might wish to pause and consider whether – with seven(!) years of Windows experience – you actually
need to "take another exam."
It's certainly an excellent idea to avail yourself of video courses that are intended for exam-preparation, and I also regularly scoop-up exam study guides
(at used book stores ...) because these things are very good for "anticipating where the 'hidden rocks' are." But I must say that, if you've got seven years' experience managing Windows systems, perhaps you will find that "Linux is actually not
that different."
Although, of course, "the
details are completely different," in general "the
concepts (and the typical
show-stoppers) ...
... actually aren't. By now, you know what to look for.
So, at this point, I'd suggest that you
trust(!) your accumulated experience and start planning-out your project. Look for potential "gaps" in your knowledge and, as you are now doing, seek to fill them. But, leverage your
industry experience to help you anticipate which "gaps" might matter, and which ones might not.
Also: "leverage
LQ!" Plenty of people here have stood in your exact same shoes ... for many
decades.
"Go ahead ... fire away." Many of the senior participants here are thoroughly familiar with Linux ... and Windows ... and midrange and mainframe ... and with
lots of stuff they don't even make anymore.
All here to make sure that you
succeed in your new endeavor. As you get your feet on the ground, post
detailed questions here.