Aside from FPGA/emulation options, somebody actually made a replica Amiga 4000 motherboard called the A4000TX[1], so if you can supply the custom chips, you can have an actual hardware Amiga.

The maker still apparently sells them on Amibay[2].

[1]https://eab.abime.net/showthread.php?t=93869

[2]https://www.amibay.com/forum/want-to-sell/hardware-for-sale/...