What about something like this Sata-IDE to fit it into the ATA100 bay? This adapter shouldn't take up any extra space that a standard Pata drive takes, used with the adapter you linked as well.
it is only 9 or 9,5cm high and the adapter is 10 or more as far as I know, you would probably get it fit before the raid adapter, but you will not get the case closed. But I heard someone using a dremel to fit it in...
RAID0 is a bad idea, anyway. I had a work colleague who bought a Sony twin HDD notebook that had RAID0 enabled as a factory default. After it corrupted for the second time I disabled the RAID for him. With mechanical drives, the speed boost from RAID0ing is negligeable compared with a single SSD as seek time is the most noticeable factor.
Anything past 200mb or so read there's no real noticeable difference to me, unless I'm transferring large/multiple files. I'm usually rolling with 500mb reads in most of my systems.