HELP deciding between a few laptops


Sep 14, 2018
Hi everyone, as the title says, I need help choosing between two similarly spec'd laptops.
I need a new laptop for high school that is under 14" as it needs to fit in my bag. I need at least an quad core hyper-threaded CPU for using CAD applications and multitasking but also needs to have decent battery life to last me a school day.
I don't really want anything dell (long story) and I have up to $600 to spend. Preferably it should have a warranty so in case something happens i don't need to worry. Please help me choose between the ones i have or recommend that would be great.

My first choice is an HP Zbook 14u G5 new 1 yr warranty with an i5 8350u, 16GB DDR4, 256GB ssd and a AMD Radeon Pro WX3100 Mobile 2GB GDDR5 gpu. A notebookcheck review says it should get 9.5hrs from its 50whr battery.
This would cost me $600 and is the most expensive option i have found that is suitable for me. However i'm not sure I need a dedicated GPU for CAD. I also play some games such as rocket league and cs go but I'm not sure they would benefit from workstation graphics.

The second option would be an HP Elitebook 840 G5 new 1 year warranty with the same i5 8350u, 8GB DDR4, 128gb, and no GPU. This would cost $525 but I plan to spend an extra $35 to upgrade the 8GB to 16. I'm not sure if the extra $40 for dedicated graphics is necessarily a big improvement for CAD and games so I need your opinion.

I also found a USED Lenovo Ideapad 720s 14" with an i7 8550u, 8GB DDR4, 256GB ssd and Nvidia MX150 GPU, and 56whr battery for $530. This is used and doesn't have a warranty which is why I am hesitant to buy it.

My last three are if all 3 above don't work out which is unlikely but i'm gonna list them anyways
used no warranty HP Probook X360 440 G1, i5 8250u (less performance), 8gb ddr4, 128 ssd, no gpu = $350 + 35 for ram upgrade
used no warranty HP Elitebook 840 G5, i5 8350u, 32gb ddr4, 256 ssd, no gpu = $550
used w/2 year warranty Dell XPS 13 9360, i7 8550u, 16gb ddr4 non upgradable, 128ssd, no gpu = $500

So what do you think? I need to decide within 2 days so any help is very useful