Hi SteveR123,
I doubt there is an option at vCenter level to change the boot order at the time of VM creation. But you can try to do it with a PowerCLI script .
You can take a look at the sample scripts below;
virtuallyAndy: PowerCLI to alter VM BIOS setting
Change BIOS boot order and Mount CD-ROM with a list of vm in the text file
If you you are able to customize the scripts to suit your needs that will be awesome otherwise comeback and post the same in PowerCLI community for help.
~dGeorgey