Please, spare us the industry rhetoric. :no There are plenty of home builders out there who are diving rebreathers with little or no formal education and they're doing just fine.
Now then, on to the question:
George,
You mention the desire for two semi-closed rebreathers, and then in the next breath speak of the Inspiration. The Inspiration is NOT a semi-closed rebreather. It's fully closed. A new one from Silent Diving (the US distributor) will cost you $9,899 US plus the training. Like it or not, if you buy new, every manufacturer I know of will require you to take a formal course, which runs about $1,500 US. If you shop for a second hand unit, you
might be able to dodge that. However, unless you've got some prior rebreather experience you probably don't want to.
I don't know much about the Submatix units. I do know that they make both a SCR and CCR. You should be able to find out some more
here.
As for other general rebreather information--I would recommend that you spend some time on
Rebreather World. You'll find lots of info and folks to answer your questions over there. You might also consider picking up a copy of Jeff Bozanic's
Mastering Rebreathers. The title is something of an overstatement, but it's full of good information nonetheless.
Hope that helps.
Brian