It depends on if you are using stock springs or not.
I personally recommend a Z-link or cross over steering with a SPOA.
I recently installed a SPOA and I'm using a CJ leaf in each stock spring pack w/ longer shackles. I have about 6" of lift and my 3" drop pitman arm didn't work. I had to use a Z-link instead. If I had any more lift I would have had to use both a drop pitman and Z-link.
i would personally spend the extra clams and get the breeze cross over unit that Tim sells (north coast off road)... i fully plan on that when i get the clams myself. got dropped pitman arm, just layin on the floor, got me a homemade zlink on my junker.
just my humble opinion!!
Do unto others as you want done to you!
If you pack it in, pack it out!
When I bought my Sammi, it had a 5.5 SOA but no modifications to the steering at all! Driveable, but I had to do something for trail riding and flexing. I added a 3" drop pitman arm and that works just fine for me. No bump steer and works under full flex. I don't see the need to go the extra bucks for the Z-link. I guess it depends on how extreme you want to be and how much cash ya got.