64" is measured from tip-tip along the belly of the bow if I not mistaken.
As Jim stated, LB's usually have 3" shorter string length that the lenght of the bow.
There are some string makers in our sponsors. They can help you out on exactly what you need.
As far as arrows, if you are draw lenght is 28". Maybe some 2016 alum. will be a good place to start.
Some more info. will get you closer to what arrow you need.
Your draw length?
How close to center is the bow cut?
What type of arrows? (wood, alum., carbon)
Good luck!