Thinkpad X1 carbon 5th edition (Intel i5 / 8GB RAM, 128GB SSD).
I have installed xubuntu 17.04 on it and it works like a charm and can easily use it for 7-8 hours.
In general, buy last year's Thinkpad with Intel graphics and wifi chips and you'll do OK. The absolute latest model will sometimes have driver issues, plus the cost/value ratio is better for a year-old model.
