I'm just downloading and will try to find out what's wrong.
Please remark, that I'll support amd64 only in the first step. That is, because nearly all new hardware (including Macs) are 64-bit machines.
You cannot cross-install on uefi, if your distro is I386-based. This doesn't work regardsless you are trying to install on IA32 or amd64.
So what seems to be most important to my is to prepare cross-installation from a computer with msdos-firmware (aka BIOS) running amd64 to a computer with uefi-firmware.
Therefore I selected to install the amd64-version of jessie-testing.
The installer is written already but has to undergo testing yet.