Packer.io Template

Question

I have 2 Input Files

1. Custom OVA with Base CentOS6.5 and all the required packages(rpm's) already installed.
2. My Application in ZIP format having install.sh bundled inside it. (app.zip)

Iam looking for a Packer’s Template which should take

1. Custom OVA, then Create a VM on ESXI Host
2. Custom Application(app.zip) to VM, Unzip app.zip , run install.sh and on install completion Generate a new OVA.

Is this Possible using packers if so , any pointers / Can any one help me with a sample template?

Thanks & Regards,