Hey darren,
Here's an idea you may want to try. I needed some straight edges a while back for a panic job and didn't have time to shop, so I made my own. I took some 1" X 1.5" aluminum angle, cut it to 12", 24", 36" & 48" lengths and used JB Weld to epoxy 1 1/4" dia. flat magnets on the 1.5" side. Worked quite nicely and very inexpensive. Hope that will help you.....Denny