Kudos to Amazon. I ordered a new graphics card (I still suspect my current card as the source of all my recent system lock ups) from them on Wednesday afternoon, picking the free (but slow) postage option. It was due sometime between next Wednesday and Friday, but showed up this morning.
Now I just have to wait until I can go home and install it - with luck I'll have a stable system again, and just in time for the weekend too.
The CMS is running nicely now. My next job is to write a decent frontend to it along with a "new article" detection script (which will look at the filesystem for articles that aren't registered in the database, add them with some guesswork about what it should be doing with them, and then let me approve or correct its choices). Then, of course, there is the rest of the TODO list which currently occupies the front page.