No pic but has anyone converted their ar to a piston drive ? What kits are decent?

I have an mp 15 chambered in 223

__________________
HAD -93' xlt supercab, 5-speed, 4wd, k&n filter,cb, fog lights
HAD-2000 Ranger Xlt 3.slow V6 4wd K&N, gibson exhaust, cb, hid's, fog lights, backup lights, interior blue lights, kenwood sub & amp, push bar, t-bar crank, frf stickers, cab lights.
NOW-00' xlt reguglar cab, 5-speed, 2wd, coil springs, "rangeriee" as my girlfriend named it , red interior led lights, and much more planned for the future!