Im looking into doing a project over the next few months alongside the kit car, its going to be made out of various shapes and sizes of steel box section, but rather than me ringing my steel merchant and ask him if he has this and that... Does anyone have or know where I can find a list of all the regular shapes, sizes and wall thicknesses for mild steel box, tube, I beam, U beam etc?

Chears.
Dunc

Try www.dyfedsteel.co.uk, or www.johnchorley.co.uk, there a couple of stockist we use and have lists on there websites

Shop4steel also list sizes and prices LINK