What are you attempting to measure, light level? What is the maximum and minimum lux levels?
Do you know that light measurements may span ranges of 30000:1 or greater? Therefore, do you want a linear or log output?
You mention an anti-aliasing filter, so you may be thinking of using an ADC. If so, how many bits of resolution? What is the sampling rate?
The requirement of a LED turning on when the LDR receives light, at what lux level does it require to turn on or off?