rc filter capacitor type
Why not a use a 20 kohm resistor and a 10 uF capacitor? These values seem more reasonable and likely take up much less room for a given voltage amplitude. There is also a good chance that a 10 uF capacitor will be available in a tighter tolerance than a 100 uF electrolytic type.

A larger capacitor will have a greater ESR (effective series resistance) and this might make the high frequency performance unacceptable for some applications. Also, the self resonant frequency (due to ESL or effective series inductance) will probably be significantly lower for a higher value capacitor and also upset the "purity" of the low pass filter.