Depends on what you need.
I have been fiddling with the idea of getting an Acer Chromebook R11 with crouton, and just SSH to my desktop (or a server) for the number crunching. Of course this will not be able to handle a full blown IDE, and it has its limitations (4GB of RAM and 32 GB SSD), but it doubles well as a laptop/tablet/standmode. And it could accomodate for your external keyboard/mouse 🙂