Replacing disks in a software JBOD array

I have a JBOD array with a 400gb Seagate drive, and 250gb and 200gb Maxtor drives, all UDMA, for a total of 850gb that I use for storing all the 'linux distros' that I download completely legally

I also of course have a Paralel ATA DVD-RW drive, giving me 4 PATA devices. (My C: Drive is 2*120gb 7200RPM SATA drives on a hardware RAID0 array).

The JBOD array (my F: drive) is just done in software with Windows XP, as its the drive I use to store stuff between C: formats and computer rebuilds etc, and I like it to be portable to any XP Pro installation. It also needs to be expandable when I run out of space every few months, hence JBOD.

The problem now is that the next motherboard I have my eye on is the Gigabyte 965 DQ6 one that THG reviewed recently. Like most intel boards it only has a single UDMA channel, meaning one drive + DVD-RW and I'm out.

I can of course add a PCI UDMA controller, indeed I have a couple kicking about, but I already have a SB Audigy that is going to be using one PCI slot, and I want ventilation room around the 2nd PCI-Ex16 slot so I want to avoid more PCI cards (if only someone would just release a PCI-Ex1 UDMA controller I'd be ok)

Anyway, this basically means I want to replace the 200 and 250 gig drives in the array with a 750gb SATA Seagate, leaving the 400gb and the DVD-RW on the UDMA channel, rehoming the 200 and 250 gig drives in my older computers.

Is there a way to copy the partitions across from the two smaller drives, say with partition magic or something, and then expand the array into the extra space as normal, or is the array tied to the physical drives and I need to build a new SATA array big enough to transfer all the data?