For anybody still looking to do this, but not wanting to spend the money on a full unit or deal with programming issues and stuff...
Full cluster overlay. Stock USDM unit. Speedo is in MPH only. LCD screen isn't split white/black like the real one, but otherwise, it's spot on. Cost was $200 from
https://www.icefabrication.com
They have one on the site, but it isn't as accurate as this one, so I e-mailed him directly for the inquiry to have him create one as accurate as possible.
Figured some of you in here might find this to be a more attractive solution.