D,if your a bit handy and you have a mig,there easy to make out of rectangular tube.You just have to make sure you weld in crush tubes inside where the centre bolt would sit and box both ends of the tube to stop any crushing,weld in a centre bolt and your away.
Mild steel tube comes in a host of sizes.Your U bolts will be the only issue if you make them too high.I have made several sets over the years without issue,and have also purchased the ones on ebay,which always need to be modified anyway, but you get nice long U bolts,i actually have an un opened set sitting on the shelf waiting for the next car i said i would never do again.