You might not be able to load certain drivers for your new hardware beforehand, since some installers won't install if they don't actually detect the hardware present, but you also shouldn't need to do that. ReDeploy should take care of getting your restored image to the point that Windows will boot, then you can install whatever drivers are needed for the rest of your new hardware. However, if you want to continue booting in Legacy BIOS mode, you'll support for that specifically enabled on your new system in its BIOS interface, which it sounds like it already is. Alternatively, you can restore your Legacy BIOS-based Windows installation in a specific way that will allow it to boot in UEFI mode, which is documented here
-- you'll need to run ReDeploy after all of that as well since you're migrating to new hardware. UEFI has a few distinct advantages over Legacy BIOS anyway especially if you're running Windows 8 or newer, so it's sometimes worth doing. However, since you're on Windows 7, the case is much less compelling, and in fact setting up Windows 7 for UEFI has some drawbacks, such as making your environment impossible to viBoot. I would say that you should NOT bother with UEFI conversion in your case unless a) you need your OS partition to reside on a disk that's larger than 2TB, or b) you intend to set up a dual boot system involving another OS that functions better in UEFI mode. And actually when booting Windows 7 in UEFI mode, you still
need to keep Legacy BIOS support enabled in your motherboard since even in UEFI mode it has some legacy dependencies.
As for Rescue Media, Legacy BIOS can boot either FAT32 or NTFS. UEFI is only guaranteed to be able to boot FAT32. NTFS support on UEFI systems is optional, but is not widely implemented, which is why FAT32 is the file system of choice for UEFI systems despite it predating NTFS. Just enable the multi-boot checkbox at the last step of the Create Rescue Media wizard and it will set your flash drive up properly.
Your Rescue Media should be set up as MBR for simplicity, which is how the Rescue Media wizard will set it up automatically. Internal disks that actually contain an OS typically get set up as GPT when being set up for a UEFI system, but UEFI systems will boot from USB devices that use MBR just fine. They'll also work with USB devices set up as GPT, and you can manually build a Rescue Media device that way if you wanted to, but using GPT would remove the multi-boot support that allows a single Rescue Media device to be used with both Legacy BIOS and UEFI systems, which is why the Rescue Media wizard doesn't support USB devices set up as GPT. Again, just enable the multi-boot checkbox at the last step of the wizard and it will set your flash drive up properly.