Me, I am partial to SLP's. I had a set and loved them (although they had a single wall flex). Had to pull them off 5 times and never had a sealing issue. SD's are damn close to SLP's, without a coating and w/o the O2 being in the right place. I'm a cheap bastard though...so I'd buy a set of SD's, have Josh make the enhancements (because all headers have a ubend that hangs down) 1. Remove U bend 2. Relocate O2 3. Dual wall flex ($20 cost of part). Then I'd hit up Frozenboost.com for the 4 clamps ($5 each). Only other thing from there would potentially be coating them.