Al Dafna is a good area to consider - a relatively good compromise between the high rents/proximity of West Bay and lower rents/distance of Al Waab/Landmark. Commute to West Bay is pretty reasonable, about 10-25mins depending on traffic. I'm staying now in Al Dafna but am planning to move to join some friends, so am looking for someone to take over my room actually: http://www.qatarliving.com/node/462794

Old Doha, while bustling, may not be good if peace and quiet are what you want. Moreover, commute to west bay along the corniche can be a snarl.