partitioning & booting

I am currently running all my applications off a HD as I was unable to install the grub bootloader on my ocz pci express card (grub won’t install on the pci express card as it is a raid0 array).
I would like to use the HD for backup only and run everything off the ocz card - with the exception of booting (which is unfortunate but I didn’t manage to make the pci express card boot).
How is it possible to tell suse during the installation to create the /boot on the HD and the rest on the pci express card and also to allocate the remainder of the HD as empty storage area??
p.s.: alternatively, has anyone managed to boot suse on a pci express card without using chroot? All fixes I tried involved chroot and all failed…

Legacy GRUB which is the default in openSUSE must be installed on a traditional PC partition whether Windows or Linux. During installation you can go into expert/custom mode to create a separate /boot partition on a traditional PC partition and put the rest of the system elsewhere. The separate /boot partition does not have to be very big - 32Mb should suffice if my current /boot folder is anything to go by.