The current tablet market is depressing.
Kindle: Kindle is garbage software, don't bother. Ereader much better for books, and books available across any platform anyway.
Android: Non-nexus devices get garbage security/software updates, except for the Shield Tablet. The Shield Tablet is recalled. The Nexus 9 is the only Nexus tablet still for sale, it's too expensive and has mediocre build quality.
Apple: Hella expensive, Apple doesn't allow emulators.
Windows: Haven't really kept up to date with offerings from Lenovo/Acer/Dell, but they've all got slower CPUs than the Surface 3, which is already expensive for lagging behind Apple in performance.
Pick your poison.
Bluetooth keyboards on tablets are kind of garbage, I wouldn't bother with a keyboard unless it connects physically like the Surface/Surface Pro/iPad Pro.
No PC is going to emulate XB360/PS3 games. Wii is essentially from the PS2 generation when it comes to emulation, and you're still not going to be doing that on a tablet - even with a Surface Pro you're realistically limited to PS1-gen games.