Best of luck to you since I would love to see this happen.
I had the same idea that I posted here last year but unfortunately all the manufacturers I contacted wanted a solid 1000 wheels sold before doing any work.
The cost of tooling for a forged wheel is enormous. I would be surprised if this is possible for the size of a group buy the members here could assemble.
Another possibility is hot-rolled cast where the outer rim is rolled under pressure to impart some of the strength of the forging process.
I agree it would hard to give up our light, relatively strong wheels. It is one of the few distinguishing features of the Marauder.