Grading bucket

Hello everyone, this is my first post. I was searching the net for any info on building a grading bucket possibly tilting and came across this forum. I also have plans to make a 12 inch bucket for trenches. I started collecting materials. I figured I would use 3/8 plate and a plow cutting edge and maybe double plate or add 1/2 plate in curtain areas. I have a 2013 jcb 3cx extend a hoe with a wain Roy xls coulpler. So I have to integrate that mount into the design. I found a 4.5 inch pipe with a 1/4 inch wall thickness I'm hoping that will be strong enough. So I still have a few questions about the design, I would like to make a curve like a typical buckets design but don't think I'll be able to bend the plate. Is there a tip to bending 3/8 plate. I was also thinking about using a section of 12 pipe and cutting an area out to make the curve. I would like the bucket to be at least 48 inches wide, should it be less or more? I would greatly appreciate any input anyone would like to offer. Thank you

Grading bucket