Despite being a bit more expensive, I find that GW paints work really well, and are well worth their cost. That and Testors are my two favourites. I use Vajello for washes though, since their stuff is all crappy and watered down anyway(their black glaze is excellent for this). I wouldn't ever recommend Vajello for anything other then washes, unless you really like your colours to be very thin and faded(see the fur on my GM's cape). And I wouldn't ever use GW paints for washes, since not only are they more expensive, but you can put them to much better use then that. Testors is good for pretty much anything. It's very close to GW paints in its consistancy and I like that a lot.
I also use Tamiya purple for the eyes of my GKs, and it's like a mix of GW and Vajello in some ways. On one hand, it's actually a very deep colour, and goes on pretty thick. But on the other, it's very watery. It's a very odd combination, but I'm not complaining.
As for tools, I use some brushes, obviously, but I'm also a fan of needles, toothpicks, and even tried out paintmarkers(they make great small brushes once they're dried out, since the tip is so small to begin with).