To be honest, I wouldn't even try. There's the issue of putting a rack on a suspension fork in the first place. There are a few ways to do it but all of them seem kludgy. None of them are cheap, either. The Old Man Mountain go for $140. Tubus makes the Swing but it's a similar price.

And loading a suspension fork doesn't do anything good for the suspending part. A load on the lowers of a suspension fork makes the fork leaden and slow to respond. You'll also need to be careful when clamping anything to the sliders to avoid damage.

Assuming that you are going to be riding mostly roads or even smooth dirt roads, you have the problem of carrying around a fork that really doesn't have much to offer. Unless you plan on doing some off-road riding...and you should probably have a different bike for that...a suspension fork is mostly added weight.

A better option would be to buy an inexpensive rigid fork and swap it out for whatever touring you want to do. The swap is simple and takes only minutes to do.