From looking at the pictures on their website, Minifree laptops appear to be old, re-branded Lenovo T400 and X200 Thinkpads.
If we ignore the fact that they're selling old, presumably ex-business machines with upgraded memory and a nice sticker on the lid, then that's still fairly old hardware. (X200s were released in 2008... You can pick one up on eBay for a fraction of the cost that they're pedalling them for.)
Having said that, I'm typing this on my old X220 Thinkpad, which is 5 years old, hasn't had a memory upgrade, and can still run the newest version of Tails without any trouble.
The Tails official requirements page says you should be fine on most post-2005 systems with 2GB of memory or more. Which Minifree laptops have.
Can you boot Tails from DVD on mini free?
Yes, if you burn the image to a DVD.
Can you boot Tails from USB on mini free?