One thing to keep in mind - you can add an aftermarket PS kit from either Wicked or SuperATV to your Z if you so choose down the road. I was really thinking a PS kit was one of my first 3 aftermarket purchases for my Wildcat, but I have yet to feel it is a necessity for my riding areas. The more important and practical upgrades for my ride were aftermarket tires (GBC Dirt Commanders - 8 ply that wear like iron) and springs to replace the crappy springs that Arctic Cat uses. I added an aftermarket exhaust which really woke up the 'Cat, and while I'm not ruling out an upgrade to power steering, it won't happen this year. I gained ground clearance and performance with those 3 mods.
Next on my list are a flip-up windshield and heated seats. That can wait til this Fall, and again it's a more worthwhile upgrade than PS for my needs.