You choose the card at the point where you either create the VM or else edit its settings.
I’m using an Earlier version of ESX1 here (5.x), however when building my VMs I chose to use the e1000 adapter, which does have a physical counterpart, and thus has Linux drivers which can be distributed under the GPL along with UrBackup unlike closed VMWare code.
Choosing VMXNET sends you down the same licencing rabbit hole as you end up when you’ve a Broadcom wireless adapter in a laptop & try installing Debian… then have to download the closed source firmware separately or install from an unofficial image. Without reading the VMware licence I couldn’t tell you if urbackup would even be allowed to distribute the VMXNET driver within the restore CD, though one could doubtless be built which includes it. manually.
You could try adding an e1000 adapter to the machine you wish to restore, restore & then remove it afterwards.