Sorry to have seemed so angry-it was just an incredibly frustrating experience!
That said. Especially the last link helped me and I think I'll pick up a WRT54GL-EU which seems to be a WRT54G v4 and thus pretty compatible in terms of open firmware.
If it works out, I'll definitely get a few of them as then they'd be worth keeping!
Oh and thanks for the notes and suggestions from both. Lovely to see even personal routers can have Linux