You are going to be hard pressed to find any computer system that will be viable solution for 10 years.
The argument that macs are expensive is ridiculous. If you build a PC at dell with the same components as a Mac uses, the price will be nearly identical, so pricing is a wash. (Apple does not make lower end computers and a $300 pc, is a lower end computer).
It comes does to your workflow. Do you wish to have portability (iPad, surface) or be tethered to a desk (desktop/laptop with a plug is drawing surface)?
If you want it to last 10 years, you need to spend some money. The question is how much?
If you buy an iPad or surface (I chose iPad), you have 0 options for expandability (ssd memory, ram) but some surfaces do allow sd card storage and cloud storage is an option.
Laptops would reduce a desk footprint but often the ram is soldered into place and is not expandable. Besides, with a laptop you are still plugging in an intuos or a cintiq. So I would recommend a desktop with a great screen, expandable memory and something that would give you a long life.
For me that would be an iMac 27” with retna display and as much ram as you can afford to purchase. then purchase the drawing unit of choice (intuos, cintiq, etc).
So it comes down to portability of an iPad (buy the best you can) or iMac.