Before I go out and buy something I know nothing about. I need a straight answer. Im getting mixed answers on this. I want to go to carbon arrows because the price of steel keeps going up and aluminum arrows arent as cheap as they once were.
My draw is 30 inch
My aluminums are 28inch 2314'swith 100grain bh.
im drawing 55-60lbs

I was told to use a 400grain arrow with 100gr broadhead. Someone told me to use a 300 grain arrow and a 100grain broadhead. I need someone to give the right answer. I cant always make it to my proshop and I will not be getting them from there. I can get them cheaper elsewhere, I just need a straight answer. On the boxes I looked at with fletchings and inserts:

I dont not know what the numbers stand for? Is it their weight? LikeI said im no good at figuring this carbon stuff out.
First box:300
Second Box:340
Third Box:400

Oh and if I cant the right arrow in 28 inches will it hurt to got 29 inch?

I can get one hell of a deal right now but need the right answer ASAP. Help please.