Its really no different than anyother 3/4link setup. The elliptical is just a spring at that point and doesnt hold the axle in place anymore. Now its up to you to get the correct spring rate that will net you the ride ht you desire. After that its all about the link geometry and the shock tuning.
As to which spring to use, I have no experience with that. Some one else, maybe BoogerWeldz could answer that one.
