This is one of my favorite Atari ST games. :) What a great review!

I have always used nextpcb.com for any of my projects (primarily hobbyist, but also for work.) NextPCB as a company is a good group of people to work with. They also do very low-cost assembly for your builds. JLCPCB is also another good company with a lot of bang-for-your-buck. I've used both.

Alternatively, OSHPARK (oshpark.com) is a nice prototyping operation. However, they don't do assembly work. If you can solder ICs, that isn't a problem. I suck at soldering surface mount parts, so I just leave that to paying for assembly service.

Out of all of them, I've had the most experience working with NextPCB.

I'm not a walking advertisement for any of them, this is just my experience with these companies.