Welcome aboard mate!
We have lots of opinions here and all of it helpful. I look forward to seeing your build here on SC. As far as getting a child out of the house, LOL, well that is beyond the scope of this site!
You may want to visit that cardiologist and share with him what is REALLY involved in getting a sub to work. At least for me there have been a few times my blood pressure has gone through the roof.
It sounds like you have a great sense of humor and the right mind set to build a fantastic sub!
If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.