Hi, Rachel!
Congratulations on your decision to participate in the 2015 Dopey Challenge!
Though there isn't a resort that will meet all your criteria; close to Epcot, two sleeping areas, moderate resort pricing- I do have some great suggestions to consider.
Resort recommendations meeting space criteria:
Disney's Art of Animation Resort- With spacious family suites available, this value level resort offers a reasonable price for the space you receive, not to mention your children will love the theming. This is not the closest option getting to/from Epcot via race transportation, but it's very manageable.
Disney's Beach Club Villas- This resort is a deluxe level accommodation offering a one-bedroom villa that not only meets your need for space, but also your desire to be close to Epcot. This is my favorite Walt Disney World resort hotel--I love the proximity to Epcot, amazing resort amenities and abundance of great pre/post race dining options.
Resort recommendations meeting moderate level pricing:
Disney's Coronado Springs Resort- This moderate level resort offers your quickest route to Epcot based on location and race-morning traffic patterns. Additionally, Disney's Coronado Springs Resort is the only moderate level resort that offers suites and a Business Class option- giving you the advantage of a moderate with club level service.
I hope this information is helpful, Rachel! Please do not hesitate to contact me with any additional questions you may have.
Happy Training!
Faith