Its pretty hard to go wrong with a FMIC since most are pretty good. As for what to get it depends on what you are trying to do. FBO look to a 7” or Helix style. Light mods a 5” stock fit with no cutting is a good plan. I got a 5” ETS because it suited what I was trying to do & has what appears to be very good internal design. Also at the time was on a group buy. Logs show it to work well holding the IAT down in my case.
They all make horsepower claims but I have no idea how valid the claims are. I got mine to manage the IAT in the Carolina summer & any WHP gain is just icing on the cake.
Thing to watch out for, like downpipes, some can tend to be way overpriced.
2013 135is Cab JB4/ISO - 2011 335is JB4/ISO/BMS Flash - 2009 V-Star
2009 Ford Expedition EL 4X4 - 2003 Xterra 4X4 - 1998 Ranger 4X4 - FFR Cobra MK-IV work in progress