In short ... not, it won't work.
As far as I know ... If you have a "Free ESXi" license, it should not connect to vCenter. If you attempt to add the ESXi host which uses the free license, it should fail stating you don't have a license for the vCenter agent.
This means you either need a paid license for ESXi, or a trial for the current versions. I think you can only get a vCloud Suite license on trial now, which will only work in vCenter 5.1.
Additionally, the Free ESXi license does not include DRS ... which is required by vCloud Director. So that's another reason to have a higher license level.
Had a feeling that was the answer. I know I could rebuild the hosts and leave them in eval mode for 60 days. Can you "remove" the license and then apply it again in 60 days?
Within the first 60 days after installation, you should be able to remove the license (i.e. set the host to eval mode) and revert to the free license again later. To assign the free license again, you may however need to remove the hosts from vCenter and disable all enabled features which are not provided with the free license.