Here is a rod with this feature already a part of the package:
http://www.fishinglessons.co.uk/blog...-rod-review-2/
Batson Forecast Weighted Butt Cap System:
http://forecastrodcomponents.com/butt-caps/
I was looking at the $699 Sage ESN 10' 3wt + Sage 4230 reel, and it too seems to have this balance issue. Like my 10' BVK 3wt (with extension kit), the balance point is at the hook keeper, and I'm using an Orvis BBS II with Cortlands Competition Euro nymphing Fly Line 2-4wt. The sage balance point is mentioned in a few threads on the internet. For Example,
http://www.georgia-outdoors.com/foru...p/t-90820.html