Borrow a hemet from a buddy just in case or you can buy one new for $40-$100. As Mike stated roll bars and harnesses are usually for faster cars 10-11 sec range. Not sure about the no electronics might want to call them. They are probably not referring to anything in your stock srt6.

Your 1/4 mile times will primarily depend on your launch. Take a tank of air and a gauge so you can adjust your rear tire pressures accordingly. Start between 22-36 psi. I know thats a broad range but if your running street radials you wont want to go much lower than 22 and 36 is a litle on the high side. Remember after a pass your tire pressure will naturally rise due to heat.