Well....it took me long enough but I finally completed these two marathons in two weeks. The second race was not as bad as I expected, only a few minutes slower. It felt worse of course but I was not that much slower. Kinda cool to get 2 states done in 2 weeks!

Congrats, Johnnybefit. A great thread and a cool ambition. Sounds like you're getting plenty of enjoyment out of your running.

For a runner of your experience, there is little need to hesitate about a trail marathon. Although perhaps it's best to wait until the ankle is 100%.

As for trail shoes, they are hardly an essential. Some runners these days may have difficulty believing this, but prior to about 5 or 7 years ago when trial shoes were invented (or strategically marketed?), plenty of runners raced all manner of distances on trails, in "normal" running shoes. And many still do. Some even win races and set course records.

Ultimately it's the most comfortable and best fitting shoe that will generally give you the least problems in long races, regardless of the race surface and specific shoe design.

A few thoughts regarding running marathons on a short turn around, whether that be 1 week or 3 weeks.

• With your experience, your body should be handling the recovery between marathons fairly well. As a point of comparison, of my first 10 marathons over a 3 year period, I managed marathons on consecutive weekends on two occasions.
  
• If you're fit and ready to race, run the first race without saving yourself for the second. The second is likely to be sub-optimal anyway, so why deliberately to run 2 sub-standard races?
  
• Time deficit for the second marathon need not be large. Some on this thread are suggesting pace reductions up to around 1:30/mile for races 3 weeks apart. That's more suitable if the races were 3 seconds apart! Like if you were running a flat 50 miler.
  

I guess my message is relax, have a go, explore and find your own limitations. You're likely to be a more capable runner than you (and indeed many others) anticipate.

Good luck. :-)

Thank you. I appreciate the support. I do like your recommendation to go for it on the first marathon. I have my next "double" planned for next spring. I am also considering running a marathon on consecutive days next fall!
Cheers, John