If you can find an X60, you can put Libreboot on it.You can try a Samsung np-nc10, wich has a BIOS, but the management engine there poses zero threat. I've posed about it somewhere on the forum, if you're interested.
Of course, there's also the EOMA68 card.
Then you have options that potentially cost more. Best to check Libreboot's website for more models.
