When you run the Qubes installer, it automatically uses LUKS/dm-crypt in the background to implement full-disk encryption (FDE). You don’t have to interact directly with LUKS at all, and you don’t have to worry about the version of LUKS. You can simply run the installer, follow the instructions and prompts, and your Qubes installation will be be fully encrypted (except for the boot partition, of course).
Customizing the LUKS options is not necessary, since LUKS already ships with secure defaults. If you still want to customize the LUKS options anyway: Sorry, I don’t know how to do that in 4.1.