You're in luck - my friend and fellow Lisa nerd, Alex, has pretty much exactly what you're looking for. The Cameo/Aphid setup was fantastic, but the evaporation of PocketBeagles has made them hard to find.
Alex's ProFile emulator uses an Arduino Mega 2560 and runs Tom Stepleton's "Selector" software (what the Cameo runs) and is very nice. I can't recall all the limitations it has vs. the Cameo but, for general HD emulation, they are probably not going to impact you. I've had mine connected to both of my Lisas running pretty much all the OSes the Lisa will run and without any issues: LOS, MacOS via MacWorks (including the PFG version), UniPlus, and Xenix. At VCFSW this year, Alex even had GEM running off of it. His GitHub repo is
here.
I may have a couple blank PCBs floating around my shop; I'll take a look this weekend and see if I can find one. If you're in the US (and I have one), it's yours for the cost of shipping.