if you're not power hungry like Gman then the only thing you need is a laptop. a docking station (or port replicator) converts it to a desktop, and the push of a button pops it back out so its a laptop again,
I think notebooks are as strong as desktops . One of the reasons I bought this notebook was to move it in Cyprus or abroad. Even now I can use the notebook as a desktop since I have an external keyboard and mouse and the notebook is on a self 15 cm height so Its in a very comfortable position.
Its a device that your notebook plugs in and automatically connects it to keyboard, mouse, monitor, printer etc. If you have one you don't need to plug and unplug all those things every time!