i would suggest the tried and true ofna shocks (front or rear according to your shock tower) in the 13 or 14 mm variety. If you go too big in diameter you run into fitment issues with the arms and driveshafts especially if you hace the revo style driveshafts...
+1 ..........
Maxx - FLM, MMM, CD Med.36x706s
Raja - FLM Ext. MM, 1512, 4s
SC8ight - MMM, 1520, 6s
D8T - MMM 1717 6s