Senhor,
VMware Converter supports UEFI since 5.1, it is supported in all subsequent versions. The difference between 5.1.2 and 5.1 is a fix in OpenSSL to avoid the risk of Shellshock vulnerability, nothing else. It is not according to the company policy to have vulnerable versions available for download, neither it is advisable for users to use such versions. Are you really sure you want exactly 5.1?