Putting $100,000 spend on a DL Reserve card and a DL Plat AmEx credit card will also get you 100,000 DL redeemable miles for the spend plus 100,000 bonus redeemable miles when the MQMs are earned. In addition, you get 2 extra miles per dollar spent on DL tickets, in addition to about 8 (estimated as it depends on your status at the time of travel) per dollar spent on DL fares, so this is just about enough for an annual D1 RT ticket if you're very flexible about dates and routes.