Willemvan,
You need to decide if you want the 4 or 6 foot length bimini. You need to configure that the bimini has to be behind the mainsheet and below the boom with the mainsail deployed in a no wind situation as that is going to determine what your measurements need to be figured from and attached.
I suggest that you purchase the bimini from this site stating the year and boat size of course the H 26 not the 260 if that is the case. I was involved in the very beginning of the design of the bimini for both of the boats and know the mfg. By the way, this site offers a good price and quality made of course.
crazy dave condon