My stand on it would be, who's going to be supporting the configuration?

If it's you, and you aren't familiar with / comfortable with setting up VMWare and managing it (I'd presume the consultants would be doing the initial setup but will the bosses keep paying their fees?) then go with the SQL cluster.

Really, to some extent, it's nothing more than one cluster solution over another. Either way, a catastrophic server failure will still result in some downtime, either while SQL switches hosts, or while the VMWare switches hosts.

Jason