Does it HAVE to be one of those cards?
The only 32bit PCI cards that can do proper hardware RAID5 that I know of are the Highpoint RocketRaid cards. These also have full open source linux support.
Really, unless you can find a second hand PCI-X board (assuming you mean 64bit PCI) then, well, a "reasonably" priced mobo is in the lower to mid £££s range. Unless you really need the boards you specified then personnaly I'd just use a PCI raid-5 card.
Check out these cards:
RocketRaid 454 (PCI/ATA)
RocketRaid 1640 (PCI/SATA)
Hope this helps!