I have the Kooks and I am happy with them. Have you checked out the Maryland Speed pricing? When I was shopping around they had the best prices.
I don't know much about ARH. I believe they are a good brand. I would recommend researching to see if they have the same type of SS that Kooks uses and if the thickness/gauge is equivalent or better than Kooks. I know I have a file somewhere where I did some extensive research and ended up going with Kooks even though they are not a true long tube header and considered midlength headers.
2013 GT, Track Pack
, Recaros, Kooks Axlebacks, Airaid CAI, BMR Rear Adj. LCAs, BMR Relocation Brackets
, JLT Oil Separator(s), Barton 2 Post Shifter Bracket
, Steeda Motor Mounts
, Barton Shifter
, JHR Clutch line, BMR adj. UCA and Mount, Kooks 1 3/4 headers/catted H, DSS Al Shaft
, BMR Loop
, Vogtland Sport Springs front/BMR rear, Strange Adj. Struts/Shocks, Extended ball joints, Steeda Bumpsteer Kit, Whiteline Tranny Mount Bushing, Borla Overaxles, BMR Watts, Vorshlag 3" Ducts