Choosing an Apple iPad

Question

iPad

The question is simple: which iPad to choose. But I don't understand them. I don't follow fashion. And, in general, I prefer android. But I want to take an iPad for work - checking the cross-browser compatibility of sites and performance. Emulators are good, but not always. I don't see the point in taking the latest version of the iPad.
Therefore, the question is: is it possible to take the very first iPad (or second) and install the firmware from the new one and / or the safari browser on it.
I hope I put the question correctly and clearly.

Answer 1

iOS 7 is supported on the following mobile devices:
iPhone 4
iPhone 4s
iPhone 5
iPhone 5s
iPhone 5c
iPad 2
iPad (3rd generation)
iPad (4th generation)
iPad Air
iPad mini
iPad mini (2nd generation)
iPod touch (5 16GB)
iPod touch (5th generation 32/64GB)

Answer 2

Do not forget that on ipad 2 and ipad with retina display there is a huge difference in screen resolution and it is likely that sites will be displayed differently.

Answer 3

Thank you! I will buy iPad 2 - I will make a gift for NG :)