I am a professional Pipefitter/welder with 30+ years experience. (I'm a Pipefitter/welder in the heating/cooling world, not motorcycles) If you can get the material type from Akropovic, an experienced TIG welder should be able to help you. My guess is that even if you have the "Titanium" system, the headers are probably stainless steel. That's the way my Akrapovic Titanium system is on my FZ-07. If it is a grade 304 stainless, it gets welded with 308, or 308L filler rod. If it's grade 316 stainless, it gets welded with 316, or 316L filler rod. My advise, is don't look for the cheapest shop. Ask to see some of their work on stainless steel. If it doesn't look as good as the OEM welds, walk away. Exhaust headers are thin (to save weight), an inexperienced welder can make your exhaust system worse if the blow holes in it from welding it too hot. If you pull the exhaust system off for the repair (which any "good" shop would ask you to) ask them to secure it to a workbench for all the welding, AND cooling down. Stainless steel warps during welding, and especially during the cooling down!!! The best way to control that warping, is to secure it so it so it doesn't have a chance to warp in the first place. Hope that helps, good luck-
"W.O.T. until you see God- THEN brake"