Roundup of 35mm adapters
 

Hi,
I own an XL1s and an Xl1 and have constantly been given different suggestions on 35mm adapters; I have been suggested the following
-LetusXL
-Brevis35
-Go35
-Sgpro
Of all of these, which would anybody advise for this camera (which has an interchangeable lens system)? I know that the Letus comes with a direct attachment system - is it possible with the others? And what are the advantages of a direct attachment system.
Thanks for the help.
Anatole Sloan