I would forget Keeklamps their so expensive, Ive used a brand in the past called Interclamp, far better value for money and in my opinion have a lot better finish than the keeklamps.
I fitted a handrail to my mothers outside stairway and their like new.
i tell you what i bought was their inline fittings so it gave a smooth top rail which helped with her arthritis ( you know how it is I'm sure) she has a problem with her grip so they where excellant for her.
I found them on the net after seeing a large set of railings at our local beach with their name on googled www.interclamp.com them and they gave me one of their distributors and it was there next day
hope this helps