Nearly all are two part, but there are a couple that are not. 510-pyro is one. Fairly easy to mix from raw chemicals, economical in use (anything from 1+100 to 1+500), and excellent keeping properties - Downside is Triethanolamine is not easy to find. Unless you have access to the raw ingredients to make your own developer solution, I'd suggest something like the Moersch Tanol. If you can find Pyrocat-HD premixed in Europe, then certainly give it a go as there is a lot more data available than some of the other formulas.
Originally Posted by Ian Grant
Caffinol is another one that is often overlooked - Might be worth a try.