Which Roof Rack to purchase for attaching a surfboard?

[Nbongo]

I need to put a 8'0 boardbag on the roof
I have just bought my Bongo so I can enjoy the north devon coast a bit more than this year

I have seen quite a few different roof racks on the market.

Cost is not an issue particularly, I just want something that isn't going to damage the elevating roof, the obvious issue is surfboards obviously create lift.
So I guess the lower you strap the board the better....

Can anyone recommend a surfboard friendly rack?
Cheers

[Doone]

This has been discussed a few times, there's a bit of advice HERE, HERE and HERE that may help.
There's also a roofrack factsheet in the members area HERE.