http://www.itsecurenet.com/virtualbox-ova-to-vsphere-ovf/ I used this < URL, in addition as per suggestion above I doubled the ovf capacity as per item 5.
So in summary.
1. Use URL above to convert OVA file to OVF files (ovf txt file and all the VMDK disk files) using VMware ovftool
2. Use the FCIV tool in the article
3. Edit the OVF txt file to DOUBLE the ovf:capacity - otherwise u get error msgs about disk capacity
4. Replacing Oracle_64 with Linux in the ovf txt file tidies things up a little too.