I think you will appreciate Seedsigner the most from what I can tell, the construction is just complex enough to be fun, but simple enough that my pre-teen daughter could honestly do it with mild supervision. It's not hard at all (as long as you get the board with the pins pre-attached, soldering the pins would be the hardest part)

I recommend nostr:nprofile1qqs06qnxfpth00tna978cdl4yryreqhrvtlycfdxh6flxwqqs02xg6cprpmhxue69uhkv6tvw3jhytnwdaehgu3wwa5kuef0qyghwumn8ghj7mn0wd68ytnhd9hx2tcpzamhxue69uhkzarvv9ejumn0wd68ytnvv9hxgtcu5hx40's web store, he provides a great service!