Need suggestion for a laptop for Dota 2

Hi,

Firstly, I cannot buy a PC for whatever reasons. My old i3 Windows laptop is badly torn (I hate it) and the performance is not great. Lags, too much heating, etc. My Macbook Air doesn't run Dota 2 well and has many times crashed. Plus playing in a 13' inch is not satisfying. So now I really need to get rid of my Windows laptop and get something decent. My ONLY requirement from this laptop is it runs Dota 2 smoothly for say medium settings. I don't have a huge budget or else I would buy the many wonderful rigs out there today. My budget only allows me to choose from a few models which are available in my country.

I have zeroed in on a few models and would like a much appreciated advice from the community. I have a few questions to begin with.

1. Is CPU more important or GPU for running Dota 2?

2. Which would be better for running Dota 2, an i3 4030U with a higher graphics card (Geforce GT 840M in this case) or an i5 with lower graphics card?

3. In case an i5 is more important, does it make a huge difference on which generation the processor build is?

Models which I am looking at and their specs are listed below. Kindly advice which would be the best for playing Dota 2.

1. HP 15.6-inch Laptop (Core i5 4210U/4GB RAM/1TB/DOS/Nvidia GeForce GT 820M 2GB DDR3 Graphics)

Price: 575 USD

2. HP 15.6-inch Laptop (Core i3 4030U/4GB RAM/1TB/Windows 8.1/NVIDIA GeForce GT 840M 2GB DDR3 Graphics)

Price: 575 USD

3. Lenovo 14-inch Laptop (Core i5 3230M/4GB RAM/500GB/Windows 8/NVIDIA Ge Force GT 720M 2GB DDR3 Graphics)

Price: 610 USD

4. HP 15.6-inch Laptop (Core i5 4210U/4GB RAM/1TB/Windows 8.1/NVIDIA Ge Force GT 830M 2GB DDR3 Graphics)

Price: 625 USD

5. Dell 15.6-inch Laptop (4th Gen Ci5/ 4GB RAM/ 1TB HDD/ Win8.1/ NVIDIA GeForce GT 840M 2GB DDR3 Graphics)

Price: 730 USD

6. HP 15.6-inch Laptop (Core i5 5200U/ 4GB RAM/ 1TB/ DOS/ Nvidia GeForce GT 820M 2GB DDR3 Graphics)

Price: 630 USD

7. HP 15.6-inch Laptop(Core Ci3 5010U/ 4GB RAM/ 1TB/ Win8.1/ NVIDIA Ge Force GT 830M 2GB DDR3 Graphics)

Price: 620 USD

Rathe than brand, I would like advice based on specs. Also, I can always benefit from saving some money if there is a not huge difference in the gameplay.

Look forward to some advice!

Thanks.