As mentioned, a good rule of thumb is that the hard drive be the master and the ROM the slave on a single IDE cable. That said, if your mobo has two IDE slots then put the drive on the primary IDE as master and the ROM on the secondary IDE as master, then no worries at all. With the drive and ROM on the same IDE you will lose time/speed when copying files from the ROM to the drive. If the drive is slave like you mention, then I do not recommend making it your OS drive, save the sata drive for that and use the IDE drive as storage/scratch space.
The sata slot, 0 or 5, does not matter.
Also, when asking about specifics for your setup, it's a good idea to list your specs.
Good luck!