Incubation temperatures??

[Thrush]

I believe that my box turtle's likely to lay eggs in the near future, and any advice on laying boxes and incubation setups would be appreciated. I need to know what temperature the eggs should incubate at, and a cheap, yet good incubator type. I was thinking of setting up a sealed aquarium with a water heater if needed, and the eggs in a container with vermiculite??
All help would be appreciated,
Thrush