Not sure of the best, but the Love TS2 is a popular controller that would work well for you. The Love TCS would also work if you want to use thermocouples instead of thermistor probes, but they're a little more expensive. I used these
because I'm cheap. By buying 3 (two for my control panel and one for my keezer) and combining shipping they were <$20 each. The Love's have a much higher contact rating, but the gas valves and pumps hardly draw any amperage so the cheap ones work fine for me.
I'm far from knowledgeable on the subject of gas valves, but I have purchased and plan on using a Honeywell VR8200A with a Q314A standing pilot and thermocouple. Sawdustguy (who seems much more knowledgeable about these than me) mentioned in another thread that RTD's are better for this application, but I already have a thermocouple that I know will work with this valve. From what I understand the Asco valves are pricey, and the way they are set up in the original Brutus design doesn't have the safety feature of shutting the gas off if the pilot goes out.
If you aren't worried about the safety issue of the pilot going out, there are cheaper valves on e-bay. Edit: Catt22 posted the valves I was referring to before I could finish typing.
Hopefully someone more knowledgeable will chime in.