issue about zookeeper deploy

hi,mailist:
i need deploy a 10+node hadoop cluster and HBase cluster, because
i use hadoop HA function ,both hadoop and HBase need zookeeper cluster

there is two way ,1 i use 3 dedicated machine to deploy zookeeper cluster
,2 i put 3 zookeeper node on two hadoop master node and one of worknode,
which one is better ? ( manager think the zookeeper cause litter
performance compact to the hadoop cluster ,so he insist on using the second
method for the budget reason ,but i think the first method is the best)