First off: Welcome.
You can power the screen off the opus or you can run it off any other 12v source(direct to battery, cigarette lighter, etc. There are pro's and con's of each. With my Xenarc I chose to run it off the DSATX and thus far have had no problems, but my system is by no means a power house. With more powerful systems, you may or may not have enough PSU headroom to power the screen. I'll let some other chime in on that.
I also thought I'd point out at that we have a MD/DC/VA meet every month (well usually anyway).
Here's the thread:
Monthly Meets - DC / VA / MD / NJ / DE / PA
Myself and I'm sure others that usually attend the meet would be glad to help you where they can. As for myself, I have limited availability, but would be happy to offer assistance when I can, though there are some limitations. I'm no guru at fabrication but I've fabbed a few and may be able to offer some advice. When you get a chance, check out the monthly meet thread and maybe introduce yourself there.