RE: what arrows
I would suggest that he shoot Easton Axis nano arrows on his elk hunt. The smaller diameter will greatly aid penetration on larger animals like elk and the added weight of the axis will aid penetration as well. They are a very durable shaft and from my experience are very consistant from one shaft to the next
As for broadheads I would definitely stick with the 125 grain heads. My choice would be slick tricks but there are a number of broadheads that will give excelent results.