Yes, you might be able to buy these parts separately and do some welding to fit them onto your vehicle, but most people would rather purchase a kit that comes ready to install. Kits come with the turbocharger of course, but there are other parts you need. They include an intercooler, manifold, downpipe and blow off valves. Some kits also come with the tools you need to install the kit.
Ram 1500s are fantastic trucks, so it makes sense that Ram enthusiasts consider ways to optimize their rides. However, a turbo kit installed by a first-rate mechanic can be expensive, so you need to budget for it.