JD Machine located in San Diego will make you a lowers with your own custom art work and I'm pretty sure custom serial numbers. I was tolld they don't have a minimum number you have to order. Their uppers and lowers are top quality. My sons and I built five AR's based on JD upper/lower recievers. Mine is a tack driver printing .3", 5 shot groups @ 100yards.
Regards,
Rick
http://www.jdmachinetech.com/