There is no difference in incubators as far as using for quail or chicken or any other egg. The difference is the incubation period of the eggs your trying to hatch, and sometimes the temperature and humidity required to incubate whatever species of eggs your hatching.
The main thing in incubating eggs is to have a stable incubator, one that will hold the temperature within 1 degree or less of the target temperature for the particular eggs your incubating. For quail it would be 99.5°F. for a forced air incubator.
Humidity for quail eggs should be within the range of 40 to 50%Rh. I incubate my quail eggs at 43%Rh, then at hatch, will increase to 55 to 60%Rh.
If using an automatic egg turner, you will need one that has quail egg rails, instead of chicken egg rails. Also, you will need to figure in the amount of space the turner will take up in the incubator.
Two other critical pieces of equipment will be an accurate, calibrated thermometer and an accurate calibrated hygrometer.
There are lots of incubator plans here and on u-tube, just do a search and you'll find plenty to decide on....some good, some fair and some you wouldn't want to build.
Just be sure to do lots of researching before attempting a build. HTH