@techlord
Unfortunately, you cannot run AmigaOS 4.0 or 4.1 CLASSIC on WinUAE. You must have an A1200 with a PPC accelerator or A3000 with a PPC accelerator or A4000 with a PPC accelerator.
There is no demo version of OS4. You have to have the correct hardware already or purchase a system bundled with OS4.
The price of entry for a new OS4 system is quite high compared to the other options. SAM460 is less expensive than the new AmigaOne X1000.
There are some used systems available. IMHO, SAM440 and SAM440 Flex are good choices for the used market. Apparently, Pegasos II systems are also a good choice. I would stay clear of the older AmigaOne systems and MicroA1 systems, unless you can see the system in action before you purchase (most of these systems are more than five years old).
If you are interested in games, an A500 or A1200 might be a good way to get started.
Sounds like you already know about WinUAE. Amiga Forever is another choice for x86 systems.
Lots of other people have already recommended MorphOS systems.
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redfox