Just a note that as of Linux kernel 4.6, my Surface Pro 3 works practically flawlessly with Linux installed natively on it, so it may be something to consider,

Just a note that as of Linux kernel 4.6, my Surface Pro 3 works practically flawlessly with Linux installed natively on it, so it may be something to consider, there's good deals on the SP3 on eBay and besides, the SP4 isn't much better. Linux 4.10 will also support the improved Type Cover 4, (currently, support is there only up to Type Cover 3/SP3)