Dave,
JeffCo does things a bit differently and the deputies use their personal number while on patrol. There will be no organized letters or numbers to tell you what precinct they're working in. You'll hear numbers typically between 200s-600s but those aren't even based on seniority.
The county is divided into a few districts and prior to a call being aired, dispatch usually announces to the deputies in that precinct that they have a call. You should hear South, South Mountain, North and North Mountain (Sometimes they'll just say mountain with no directional.) All of those get disaptched on LE 1, rarely are the tactical channels used. You're correct that you live in the South area, generally anything south of Alameda is considered the South District, minus the City of Lakewood.
If your radio isn't too busy already, Denver Police District 4 patrols a good portion of that area as well as Lakewood. The corner of Wads & Qunicy is practically covered by 3 fire departments too. West Metro & Denver split coverage there and the neighborhood on the SE corner "Lochmoore" is actually Littleton Fire.