DLSIZE, a useful resource is the
Flight Wizard/Multiple Stops Search function of
http://www.expedia.com/ I would research various flight possibilities using this tool, and for comparison purposes, round trip pricing using
Flight Wizard/Roundtrip Search. I would also secure the services of competent travel agents for their best pricing and professional assistance.
Due to the lead time of your itinerary and advance
RT purchase discounts available, I believe I would save considerably, booking round trips vs one-way segments. I'm not positive though. In the end, I would probably purchase round trips, with the
"intent" 
of using the return segments at later dates, coordinated, for a reverse trip. Just a thought! Do your homework and Good Luck for a safe and successful journey!
[This message has been edited by MRLIMO (edited 07-24-2000).]