you are about two years too late with that qusiton
Continental no longer plays with Delta/NW, and as stated, world perks no longer exists.

HOWEVER: Can't you use your skymiles for gift cards and then buy whatever is of interest to you from any store?

Check out the skymiles marketplace where you can use your miles for good, and services, including american express gift cards. The exchange rate varies but if you are really trying to burn miles, this might be the way!

https://marketplace.delta.com/index.aspx
You will have to sign in with your SkyMiles account to see the actual pricing...