Dude, I tracked with an Eibach Pro-Kit, which is basically OEM replacement. Your F&F will be fine. Supply your own helmet if you can, but yes you can rent one. You will need your windshield fixed though, so get on that.
I am not sure I can do the 18th, my car is going under the knife soon to fix some issues. Also, the likelyhood of you going off track depends on you. I never went off track until my 3rd event.