V&H Dresser Duals ( True Duals as they are also called ) then his choice on mufflers, CFR, Rhineheart 4" V&H , Stock, all depends on what kinda sound. HP and Torque are all too close to call and then it depends on the Tune. I like SE Race Tuner, Again everyone has their opinions, Mine is ,you pay 37K for A Harley Davidson Screamin Eagle Motorcycle and the engine they engineered and chose, why not use their Tuner ? Who knows their motors better than they do ? NO ONE... 110 years of making motorcycles, Enough SAID....Everybody has these crazy Dyno numbers with just a pipe and tuner..Cmon Man!!! If I can change the miles on my old car by 50K somebody can put 120HP on your 110 motor with just a pipe swap and good tune.So in the end the Header and Tuner will give you in the seat gains and about 10-12HP and or maybe a little better, and cool the bike down considerably from stock. Again, I feel the Mufflers are more of a sound preference than anything else. I like moderate loud so I listened to a lot of buddies bikes and chose Rhinehearts, Now the best sounding and baddest was the CFR, very deep authorative rumble but rode my buddies with mamma on the back and it was NO WAY. Enjoy your New bike my brother. The only better feeling in the world than a new Harley was the birth of my two sons and my freshman year in High School with a cheerleader named Jenny.