Hi Pete, I bought my Yonex irons from the American Golf shop in Romford.
The custom fitting is free (but we all know it's added onto the price of the clubs!)
I think all of the big golf superstores now offer custom fitting as part of the service.
There was a big difference in the performance of my new clubs compared to my old ones, so I'd say getting your clubs custom fitted is as important as the clubs are.
During my selection process I selected all the clubs that I like within my set price range.
Then into the driving bay and had thirty minutes hitting them. We then selected the three irons I liked the best, and finally we wittled it down to the set I bought.
They didn't try to push me in any certain direction regarding the irons, although I wouldn't let them if they tried!
Russ