Shoes?

Less than a week to Honu and I'm having shoe concerns. I purchased a pair of Ecco Biom's about 5 weeks ago and I love the shoes; however they are designed to promote a more natural running technique which requires a lot more muscle endurance on the calf muscle. With that being said I don't know if the calves are ready to work that hard for 13 miles. When I bought the shoes I made a small adjustment to my cycling cleats, moving the cleat further to the rear of the shoe which moves the focus away from the calf when your on the bike, saving the calves for the run. Everything is working just as I planned; however I'm concerned that the calves just are not ready. The second issue is that the course weaves through the golf course of the Fairmount Orchid Hotel which includes grass, dirt, crushed lava, asphalt and the wonderful concrete. These shoes coupled with concrete is not a good combo as they have very very little cushioning. My other options are the Zoot TT's or Nike Luna Racer, neither of which I've been running in lately. ????