ETS is real clean install. They have a good reputation as well. They provide the extra brackets you need to move the radiator overflow tank etc. they don't just tell you "nope you have to figure it out." It comes with an intake and I don't have to get one custom fabricated.
Their FMIC also comes with brackets for the piping which is nice and makes it more solid than just hanging around and only clamped together by the hose clamps.
All in all, their kits seem to be the most complete and require the least amount of engine bay modifications for it to work.