I'm a web developer myself and use vim as my primary editor. I think that editing through n800 could be quite painful if you're planning on more than just quick repairs. I'd set up a separate LAMP server and edit the files through ssh as you're planning to use vim anyway. That way you wouldn't be tied to the tablet, but could also code with a proper computer if you get a chance. It would also cut down the risk of forgetting three months of work to the bus.

edit: oh, you already have a server. Try ssh. You'll love it Also see ssh-fs.