Deep learning laptop

Table of contents:

• Lenovo Thinkpad E590
• Lenovo Thinkpad P53s
• Dell Precision 3540
• Dell Precision 3541

I'm about to start my Master's degree in Data Science, I foresee that I'll use the machine for Machine Learning, Deep Learning and in general AI applications, as well as for software development (C/C++, Java and mobile field). My needs, apart from supporting all the above in a work context, are battery life and mobility (weight in particular). I will not use the PC for gaming. 

I would like to stay within the $1200 budget, not much more.

I've only been using linux for years, so it would be nice to be able to have a machine that comes directly with a preinstalled distribution, so that there are already those optimisations for the hardware that I might otherwise not have if I bought a pc with windows and then took it out. At the moment, basing on this review https://python.org/best-laptop-for-machine-learning/ I have seen these models:

Lenovo Thinkpad E590

Lenovo Thinkpad E590 configuration with: i7-8565U, 16GB RAM, 512GB SSD, AMD RADEON 550X with 2GB dedicated. Cost 1195 Euros. Weight: >2.1kg
Perplexity: I don't know the exact weight, but the basic version without dedicated video card, and with a halved SSD starts at 2.1 kg. If possible, I would not want to exceed 2 kg. This one runs Windows, so there is the doubt that as soon as I mount linux something will go wrong, the battery management will not be optimal and all the related problems. Otherwise the price seems honest.

Lenovo Thinkpad P53s

Lenovo Thinkpad P53s configuration with i7-8565U, 8GB RAM, SSD 256 GB, NVIDIA QUADRO P520 with 2GB dedicated. Cost 1439 Euros. Weight: 1.75 Kg

• Pros: it comes with Ubuntu and weighs little. There is also a three-year warranty included.
• Cons: For the components it has, it seems a bit expensive. There is the fact that this price includes Windows, so I think it will cost me about 100 euros less with Ubuntu.

Dell Precision 3540

Dell Precision 3540 configuration with i7-8565U, 8GB RAM, SSD 256 GB, AMD RADEON PRO WX2100. Cost (without Win): 1338. Weight 1.83 Kg

• Pros: it comes with Ubuntu and weighs little. There is also a three-year warranty included.
• Cons: it is a bit expensive, the video card is less powerful than the one on the P53s.

Dell Precision 3541

Dell Precision 3541 configuration with i7-9750H, 8GB RAM, 256GB SSD, NVIDIA QUADRO P620. Cost (without Win): 1289. Weight 1.97 Kg
PERPLICATIONS: The processor is newer and performs better, but consumes more power. However, it is true that the battery is bigger and that is also why the weight is a little higher. The graphics card is better than the other machines, so the price seems a bit more honest.

Given the usage, weight and budget requirements, would anyone be able to help me decide? Or, do you have other proposals that you consider more valid?
Brand considerations are also welcome: both are well-known companies, and the thinkpads have been recommended to me by many people. One aspect that might be important is the ease with which parts can be upgraded and the quality of the warranty service.

See also: https://www.apple.com/