Roofrack advice

Hi everyone,
I'm thinking about roofracks for The Mighty Mazda purely to take light stuff and 2 bicycles (they take up too much space at the back). I have a gutter-less roof. I went into That Cheap Store and found Pro Trak (?). I also have a shot at buying a basket off a Disco (shame, a cross the Mazda will have to bear...) which I'm thinking about using in conjunction with the racks.
Weight capacity is 65kg across both; more than I need I think.
I did come across Rak's site courtesy of a search here, but what concerns me are the staps needed to hold the racks down onto the body that go under the tops of the doors (does that make sense?).
Has anyone had any damage caused to the roof or inside of the doors from these straps? I used rubber on a set back in Africa, but then sealing the door in the wet is a problem (yes, I know it doesn't rain in Alice much....) Does anyone have anything to say for or against Pro Trak or these types of racks?
Thanks!