(said in the best possible way) - You are crazy to think you can get to Epcot by 7:30pm. Dinner at best will take 1 hour 30 minutes. Any less than that and you are just bolting your food and if you are going to do that, you might as well just eat fast food.
Disney transport will take at LEAST 25 minutes if you catch the bus right away and THEN you have to get into the park, through security and walk all way to the back of Epcot. Not going to happen.
Honestly, pick one or the other. Why not eat at Epcot if you want to do the Candlelight Procession? This way you are stress free. Rose & Crown or Le Cellier are nice choices OR you can eat at the Flying Fish which is also lovely and a LOT closer to where you need to be.
Just don't want you to be nuts and get to enjoy your food.