The "where" and "when" are important questions to narrow down your questions. Striper can be chased year round on the fly. But where and when change flies and lines depending on the situation. Assuming you are referring to river run fish I would say most use an intermediate fly line with the rear portion being a floater for mending your line in the current. Scientific Angler Clear tip or RIO Outbound Shorts are both good lines. As far as flies. I mainly use minnow patterns in the 3-4 inch range like Eflyz and clousers. Chartreuse is always a good color choice.