You may also find a more faithful replica of the Altair 8800 here https://altairclone.com/ though admittedly the IMSAI with its big coloured toggles is much more eye-catching.
There's also a very affordable (< $100, including the needed Arduino DUE) workalike that pops up on eBay every now and again...I bought one: https://imgur.com/a/qntqSMG
There's also a very affordable (< $100, including the needed Arduino DUE) workalike that pops up on eBay every now and again...I bought one: https://imgur.com/a/qntqSMG