Stainless cable, 1/8"
Stainless thimble and clamp set - need 2
Stainless loop/hook turnbuckle (5-pac shown, you need 2)
Basically just walk into HD and find the cable and rope section. They'l have spools of SS wire rope and you can just pick the size you like, measure out however much you need, and cut it off. Based on the size wire you use, pick up some clamps and thimbles. Then grab a couple turnbuckles. I think you'll want the style with a loop on one end and hook on the other to make them easier to mount.
You'll need to figure out how you want to attach them to your bull bar and rack - the tube clamps shown above are a good idea but you could simply drill a hole and use SS eye bolt and nylock nut.
Keep in mind you will probably have to remove or at least loosen them significantly to open the hood which is one of the reasons I've never run them. I've seen some kits that have a quick-release cam instead of the turnbuckle to that end.
If you want help with it I'm happy to give you a hand; I think I even have some of this stuff sitting around my shop from an old landscape project, but I won't be home until Monday.
Lots of ways to skin this cat.