There's really no "coil over" for a 2000 Town Car...., there's front springs and shocks and rear air bags, or rear springs, both with shocks.
I like a 29.5mm CVPI stabilizer bar in the front with Motorcraft OEM shocks and a 21mm stabilizer bar with OEM Motorcraft shocks in the rear. There is also a "handling package" you can put on these cars, but if you're looking for performance, a Marauder might be the way to go.
It all depends on what you're after, me, I wanted the ass end sway and rolling in the corners out of mine, and with that set up I got it, I have gotten rid of the air bags in the rear and added variable rate coil springs and Moog end links with the 21mm stabilizer bar in the rear and the 29.5mm CVPI stabilizer bar in the front .... Not really a performance set up, but it did get the body roll out of it real good.