The bow design, your draw length, etc... all make a difference and if you are getting a full 60lbs, you may want to get a test pack. Bob Morrison sells singles...depending on your draw, the bow design, etc...the 340's might be right. It will be btwn the 400's and 340's, but you'll need both to determine it.
The weights you have listed above are fine and you won't have a problem meeting or exceeding the 460.
I am currently shooting 29.25" 400's from a 54# Zipper with 250 up front...drawn to 28+ish...my Zipper is braced very low. Every bow and shooter will have slightly different results...it pays to play.