The P3 line of inks is pretty good too. I haven't tried out their green, though.GW washes are nothing like their old inks.
I'd check out Reaper Master Series or Vallejo's inks. Both companies' product are basically identical to one another. I use Reaper inks, and I have really good results with them.
Now, I hate to bump an old-ish thread, but I've come across the same issue while trying to follow along the 'Painting Lava Bases' tutorial which requires both Yellow and Red Inks.
Looking at the only Vallejo page I could find in English, there is Vallejo Game Paint and Vallejo Model Paint. Which of these should I be getting as substitutes for the old colours (model or game)? My local hobby shop has only Citadel and Vallejo, which is why I'm asking for that brand specifically.