I'm a functional gun guy, not a dream gun guy, so not sure I can help much. I'm much less functionally inclined when it comes to fly rods.
I'd find out a lot about what the intended recipient likes and lusts after. There are a ton of very good fly rods out there, but you'd have to know me pretty well to know I'd want a classic varnished (not impregnated) cane rod; one best suited for trout fishing on larger rivers and ponds--something like an 8' or even 8'6" 5 or 6 weight; preferably from one of the Maine companies who made fine rods in the mid 20th century; and of those, a strong preference for Payne or FE Thomas, and would really go gaga over a Payne 202 or an FE Thomas Special.
These kinds of consideration in the shotgun world would be things like maker (US or Euro? Modern or classic?), S X S vs OU, gage, barrel length, etc. All of which are highly personal, and about which people tend to have strong preferences.
When someone gave me a similar gift, it was in the form of a gift certificate to a modern rod maker they knew I admired, and they let me work out the details with the builder. I got exactly what I wanted, but it was no surprise.
I did not go with my gut and have them reproduce a Payne 202, but went with a more modern taper instead. It fishes very well and I have not regrets, but there is always that twinge that I should have gone with the classic.