You should try to get another KHS-400A laser, although I heard that KHS-400B lasers will work too.
I also heard that KHS-400C might not be mechanically compatible with the SCPH-10000.
By the way, there's a compatible laser called the KHS-400Q that
might work too, since it's a KHS-400B compatible.
And there's the KHS-400W that is a compatible laser that seems to be designed to work with the SCPH-10000.
Of course, these are compatible lasers, and are not manufactured by Sony.
It's up to you to decide whether you would want to trust them.
As for the X-modules, you cannot get them legally if you don't own a newer console.
Those modules are taken from a BIOS dump of a newer console, and are copyrighted by Sony.
As TnA said, you can find them if you did a Google search for "xmodules.rar".
It's because there's no post in this forum that says that the X modules can be found in an archive named "xmodules.rar" on the Internet via a Google search.
For the rest of us that use Google often, we'll automatically search for it, but newbies won't know that.
Perhaps that FMCB install guide for SCPH-10000 and SCPH-15000 consoles can be updated to state that?