Just got myself some 10mm Ali plate from fleabay for a (what I think is) bargain price.....aluminium plate 10mm thick 2200 x 950 mm approx 87" x 37 1/2" Pickup floor | eBay Now going to look at the design and get drawing some parts to get made :D Need to invest in a pillar drill now to get all the holes drilled nice and square!

Jonathan, I've been looking at the 20mm rails and you're right they're not that much more so will get them...