On the choice of 'line' talk to Steve Godshall ... he's right across the room from Bob. He builds custom cut fly lines, he knows the rods, all he needs to know is the 'who, what, where' where you're going to fish same.
All of his lines (most of my 2handers are loaded with special cuts) are one offs. You and I may have exactly the same rod, but the 'odds' of you/I getting the exact same line are pretty small.
Same grain weight, but over a foot or two more head, etc.
Line won't cost you a penny more than something off the shelf.