Originally Posted by Adam1222

Your Marriott points are transferrable as follows:
http://www.marriott.com/rewards/usepoints/morerew.mi
They do not transfer 1 to 1, but 300k Marriott points will equal about 100,000 miles depending on the airline.

Delta will not have one way awards until 2015. You will only be able to book stopovers until 1/1/15. So if you book after 1/1/15, you would need to book as three separate awards.

You almost definitely do not have enough points to book a first-class roundtrip award on any airline.