The way that they did it, and why they did it are two totally different discussions. Will I replace the restrictive factory headers with better ones because I don't like the way ford went about it? Yes. Should I remove (and not replace) parts that they put in place for a reason? Thats different.
But anyway, back on topic. It would seem that it doesn't really matter which isoloators, as long as they are made of sufficiently hard enough rubber, so as to be up to the task. I've seen instructions on certain bushings before, telling you to grease them up before installing them, or they'll squeak. The isolator is essentially a bushing, so I was wondering if there were any... considerations that one needed to take into account when replacing them.