Yes! You can have Epcot's pastry team make you a custom cake for the party. For the vow renewal, if you go through Disney, the lowest-key option is Memories for $2,495, max 6 people. Escape starts at $5,000, max 20 people. For the train station you'd have to do a Wishes event, which has a $10,000 ceremony fee and a $10,000 Enhancement Minimum for Magic Kingdom, and then food and beverage minimums of $100-$175/person, depending on day of the week and time of day.
Cheaper non-Disney options are Shades of Green (if you have a military or government sponsor), the Swan & Dolphin, Four Seasons (amazingly, their 30-person package costs less than Disney's Escape event), and the Characters in Flight balloon at Disney Springs.