Also, I would like to get an extra mag or two. Where can they be found?
You can find them once in a while on Gunbroker, create a search and then request email notifications. They are costly though, I paid $125 for an original 1910-era magazine for a Christmas gift. Aftermarket ones are also available for $30-50, no guarantees that they will work (as well) but they should be OK as long as they are for the Hammerless guns and not the Mustang, etc.
There is a difference in the magazines (rounded or straight top) depending on whether the gun was made before or after 1926, so it helps to know what you need. www.coltautos.com
is an excellent resource.
Here's a pic of both of my Model 1908 guns -