Dats simple!
U need 2 hardisks for total 8 primary partitions!
1. Create a boot partition with ranish partition manager!(Say 10 Mb)
2. Create a swap partition (I donno whether the two linux can use the same swap partition,well check it out urself)
3. Create two ext3 partitions and a two windows partition!
Now save the partitions
4. Install 98 then Xp!
5. Install Mandrake on one of the ext3 and then RH9!
Please remember to format the corresponding partition when the OS is being installed!