Thanks for the swift replies chaps. As always someone has found something that I couldn't (cheers ChrisW)
I think the gadget guy solution is the way to go for me, I just prefer bolts to zip ties when it comes to securing hundreds of pounds worth of kit.
The Touratech bracket may be OTT but I like the idea of it locking as I just know I'm bound to wander off and leave it sometime and come rushing back to find my new toy has walked
.