I can't really say what will work for you, but here's how I do it: our company only has laptops, so my work (web dev) machine is a laptop. In the office though I've a 24" monitor, along with external keyboard and mouse. Essentially the laptop is just a portable cpu when I'm sitting in the office. The nice thing is that I can take it with me in meeting rooms, go code on a sofa for a while, work in the train or wherever I feel like. It just takes 10seconds to unplug stuff and I'm good to go.

At home I have the same keyboard/mouse/monitor, backed by a aging desktop machine, but I can still plug the laptop in the whole system fairly easily. The monitor has two inputs so there is a spare cable for the laptop, and all the external stuff is plugged into the monitor which has one unique usb cable that I can plug either in the desktop (using an extender sitting on the desk) or in the laptop.

For data syncing, well the code sits in git repositories on machines that are accessible at any time. The rest is mostly provided by google apps or Dropbox-synced for the rare things that can't be cloud apps. I even have applications sitting with all their data in dropbox, so that I don't have to replicate settings changes between machines, and also for backup purposes.