Well, I dont want to throw a wrench in this but I dont agree about the sizing. The RT will fit you fine as well. I am also 5'8" and 175 or so. The RT fit me GREAT and was one of my favorite armors. RT is only 5'10" or so and about 170 I think. He made it for himself originally. I have seen his armor on many people and it pretty much always looks great. Now - IF you are overweight, this armor will cover it up nicely. It also comes completely trimmed, and nicely done I might add.
That being said, I too would buy the AP, because its more authentic than the RT. Its a bit more in cost though, and you will have to cut ALOT.