While it might be fun to mess around with a Cisco router on your home network (I totally understand that!) I wouldn't recommend it from a learning point of view. Your scenario is going to be too tiny to explore any of the more advanced functionality of the router, which leaves you with basic port configuration, and that you can learn on almost any hardware.
For your learning needs I would recommend Dynagen/Dynamips http://www.dynagen.org/ which lets you emulate modern Cisco versions. It lets you create topologies that are actually realistic and try out various protocols. If you want to you can connect your emulated environment to your normal network.
If you want physical hardware the Cisco 1800/1900 series (or the similar Juniper J series if you want to learn Juniper) are probably what you should be looking for. But you will be paying a significant premium for a lot of features you have little use for in your home network.