you most likely wont have to rejet with just the pipes until you get a better breather, then it will be needed. You can get your sound without anything but the pipes. If you want the whole performance pack you should jet it and get a breather and go ahead and get the ign set too. If you really are into the performance you should not get those drag pipes tho, they are gonna cost you torque where you use it most.
I am happy with the short shots, got the quiter baffles coming over the next few days justto take the edge off them and keep onside with the dick and dickless tracey's.