The standard AC Delco shock available for $19 or so at Autozone (or $18 cdn at Canadian Tire

) does very well in NCRS judging if repainted the correct greyish colour. Adding the correct date might get you- let's say 1 point per shock more- or 4 points per car, out of 4500 total. Hey, that's almost .1% increase!
There's good value for money!