Conduit connectors can be purchased at any store that carries hardware and electrical equipment. For instance, many electronics stores will carry these connectors, but hardware stores like Home Depot are better bets.
One could purchase aluminum conduit at home improvement retailers such as Home Depot, Lowe's or Rona. One could also order it through a wholesaler such as American Conduit.
One can purchase electric wire connectors at retailers such as Lowes and Home Depot. One can also purchase them online on sites such as Amazon and eBay.
One can purchase Conduit blenders at many retail stores. Some stores include Home Depot and Canadian Tire. There are many styles and models which one can choose from.
A conduit connecter is a connecting piece used to connect two individual conduit units together. Conduit connecters can refer to both electrical conduits and pipe/plumbing related conduits.
One can purchase spade connectors or spade terminals from a number of online and physical sources. For example, one could purchase these products from Radio Shack.
The connectors are those things that exotic
One can purchase amp connectors from a vast range of suppliers including Galco, Mouser and Crystal Electronics. There is also a wide selection on the Amazon website.
One can purchase a variety of products from Westco some of them are: wire and cable, lighting, conduit and raceways, boxes and enclosures and wiring devices.
You can purchase XLR to RCA connectors from the Guitar Center website. Alternatively, you can purchase these connectors online from the Amazon website.
You can purchase a panduit connector online from the Mouser website. Alternatively, you can also purchase these connectors from websites such as Newark.
If the existing conduit has not been intentionally or accidentally interrupted it is still an adequate ground. If you are in doubt about this or if a test proves that it is not grounded, new conductors including a new ground wire can be pulled inside the conduit. If the existing conduit is flexible conduit and it has "jake" type twist connectors, rewiring with a ground is advisable as those type of connectors do not maintain a good ground connection.
You are talking about two different wiring systems. A conduit system uses fitting that are approved for it. The same thing applies for cable wiring systems. The fittings, particular connectors, for these systems are not interchangeable.That said some junction boxes can be used on both systems but the proper type electrical connectors, of the system that you are using, must be used to connect to the box.