In your shoes I would suggest either the Surface Pro 3 i3 or the Surface Pro 4 m3.
The reason why I wouldn't suggest the Surface 3 is because the Atom processor is sluggish and the device charges horrifically slow using micro USB. For comparison sake, my Surface Pro 3 fully charges in an hour or so but that's because the charger is 60 Watts, the Surface 3 is vastly slower.
Getting to your actual usage of the device, all of that stuff can be easily done on an i3/m3 Surface Pro. The horsepower is there but if I am being honest, the tablet experience is not that great.
As a whole the software lets down the experience vastly, there is limited "tablet" apps and frankly the user interface isn't that optimized for use as a tablet. The iPad is a much better tablet and media consumption device than the Surface Pro 3/4 and it also boasts better battery life and better standby behaviour. On the other hand from a productivity standpoint, the Surface Pro is vastly superior.
As an example of my use cases, I own an iPad Air 2 and a Surface Pro 3 i5. When it comes to doing real work and taking notes in classes, the Surface Pro 3 is my go to device. When I come home and want to relax for a bit and maybe watch some Netflix or browse the web, I use the iPad as the experience is much better than using the Surface. In my eyes these are two different devices designed for two different purposes, both can attempt to do the others job but the experience isn't the same.
For me as a student there really isn't a better device than a Surface Pro 3 but that's due to the Surface Pen being extremely valuable for note taking and school work in general. In my eyes I view the Surface Pro as a thin and light laptop with pen capability, I rarely if ever view it as a tablet. Even Microsoft themselves have shifted away from the "best of both worlds" marketing and the new Surface Pro is solely marketed as a laptop.
My main point being that you should only really pick up a Surface Pro if you need access to full windows programs and also need the pen capabilities daily. Otherwise for general content consumption an iPad or Android tablet would do a more satisfying job.
Also keep in mind a Surface Pro 3 will arguably have better battery life than a Pro 4 as the battery capacity was decreased in the Pro 4. Regardless of the device, you should expect to get between 3-6 hours of actual usage depending on the usage. Also if you do get the Pro 3, invest in the Pro 4 type cover as it is vastly superior to the Pro 3 type cover.
