you could also get some external enclosures to put you optical drives and ide hdd in and plug it in through usb:
external enclosure list
just make sure its an ide interface.
Also some ppl may say its slower through usb, but im using a 400gb ide seagate hdd in an external enlcosure with a usb 2.0 connection, and i watch movies form it all the time and i havn't noticed any lag.
Also if you plan on leaving the hdd on for a while, get an external enclosure with a fan for it. The optical drives will be fine without a fan.
edit: sry i didn't answer your last question. I'm not too sure about a cable that converts sata to ide. I did some searching but all i found was usb cables to ide/sata, but external enclosures are prob the best way to go besides the pci to ide card.