Dave's advice is golden IMHO. Also plan and scope out the wiring routing. Over the years I have changed some of our boat's routing of wiring, DC and AC cables, and plumbing, to both shorten some runs, and make others more logical for trouble shooting in the future.
The factory was building out systems on a production basis as interior modules and parts were being installed, and trying to control labor $, and sometimes this resulted in undesirable choices way out in the long run. You can do your research and tap into the longer-term and curated knowledge base here and on some other boating sites.