I think you have a fantastic overclock right now and while a peltier might give you another small bump, it also might be worse without watercooling. Peltier 72W + Processor ~40W = 112W of heat dissipated into your case, which will make your case temp go up which will make your hsf perform worse. All of that kinda makes it really not worth it unless you have a major windtunnel case and you can move the kinda air needed to draw away double your current heat.
So its really not worth it.