In reply to anatso: Can you clarify, unless I have missed it, do you mean hill climb bike as in the sport of hill climbs in the late part of the season normally only seen in the UK or do you mean 20k alpine cols ?
If its the former you could do worse than do a search on Jack Pullar who is the reigning national hill climb champion, there was some articles on his bike in the mags, weight was first on the list, there was never any mention of geometry.
If it's the latter then any road bike with race geometry will work.
I am struggling to see any benefits in a bike with custom geometry over an off the shelf bike with race geometry for either option though.
I am however willing to be educated........