Linux Mint Debian Edition would be a pretty solid, pre-customized distribution.
I've had great experiences with Linux on Lenovo over the years: would be my first recommendation.
I currently use a Dell Inspiron, while it's works great, I had to do some extra work occasionally. I love that I can get fingerprint login with it on Linux though.
This is the caveat for me for now.
I've got decent RAM on an I9, but my graphics card, which is what matters here, isn't up to par.