oh I have no doubt you shop can do one. That cylinder head above has no coolant passages in it... I would recommend getting an engine parts book, picking your valve, spring, retainer and bucket/rocker. Then building the head around it in cad. Cams can be CNC ground. Heads cut from billet. Design your seat pressure and your opening pressure for your flow/lift of your new design.
if I was doing it. This is how I'd start.
You're going to need a flow bench for a stock head, a scan of that head. Import them into a FEA flow analysis program. Compare real results to your virtual numbers for a baseline.
Take your new design, and then flow it virtually determining what you're hoping to improve on. Understand that the main advantage of a DOHC head is flow, 16v's, better squish for flame propagation, and better lobe profiles. Most DOHC can run a more aggressive opening lobe profile allowing the valve to open faster and with less resistance. Do understand that due to the long stroke of the m10, high revs such as 8500-9000 rpm create exponential loads on the connecting rods. It can be done. just not for long. a DOHC roller rocker m10 with an 8000rpm redline would be a nice machine and would be "streetable" given proper cam overlap profile. There is alot of engineering here before we make our first chip.