Auditing a network to add Voice

Hi, My customer would like to add VoIP over their network and they asked us for an audit. the result of the audit would be simply "you guys are ready for it" Breaking it down [high level] for me sounds like : (suggestions are more than welcomed) : 1) Looking at hardware computation finite resources (cpu, memory...etc) 2) Looking at available bandwidth 3) QoS policy 4) High Availability and Fast Convergence Any thing else? They asked us to measure the KPIs (jitter, delay...etc) of their existing traffic, is there a way to do that? Thanks, Kim