microcontroller/dsp design for 12 bit true RMS voltage to digital conversion

I need a digital true rms to digital converter. Source is a current transformer 0-1vac for rated turns ratio. I just need a i2c output. 2 wire input to board is floating 0-1vac to a 100 ohm resistor. 5vdc input (2 wire) with a 3.3v i2c interface(3 pins). There is many examples of hardware/software for doing this on the internet. I would like to use microchip but any low cost solution will do. Quote design, pc board layout and working sample as 3 different quotes.