@cehoferSorry to see you are having such difficulties. Way back in 2004 I purchased a MicroAmigaOne motherboard from a dealer in Eastern Canada. It came bundled with a pre-release version of OS4.0. Like you, I sourced the other parts locally and put my system together myself.
The dealer (Justin) helped me out alot when I was first starting. At the time, I was probably the only customer who was not a betatester or developer. And some really helpful guys in the forums also helped me.
Sorry I can't help with SAM or X5040 because I never purchased those systems.
I hope you find some help. Some of the experts hang out on Amigans.net. Amiga.org and Amigaworld.net have become ghost-towns for OS4 related stuff. A few old timers like me still hang around all three websites.
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redfox