on death:
victim is zombie
attacker is player
clear drops
remove 1 from {zombiecount}
broadcast "%{zombiecount}%"
add 2 to {money::%attacker%}
add 1 to {xp::%attacker%}
You'd have to clarify the money and xp variables as {money::%player%} and {xp::%player%}
btw instead of using clear drops you can disable drops with /gamerule doTileDrops false