I guess if you want a large phone with removable battery and micro SD slot, a Samsung Note is your only option I can think of.
I prefer the 6 or 7 inch screens for reading. Two reasons. First they light weight, they are more comfortable to hold longer periods. Second reason is with larger screens your eyes need to move around more to take in the larger surface. It's a minor issue, I can read fine on 10 inch screens, but find it a bit more comfortable on the smaller 6 or 7 inch screen.
It fails to meet multiple requirements, but the Nexus 7 is a really comfortable tablet to hold. Google made the portrait bezels thinner so you can grip it with one hand comfortably to read with and the back feels really nice. I have complaints about the Nexus 7 color quality and pathetic speaker, but when it comes to reading it's just amazing.
Oddly the Kindle Fire is great at watching videos with it's great screen and speakers, but kinda sucks at reading books (go figure) because of it's wide bezel, it's squarish edges, and it's heavier than most 7 inch tablets.
I picked of a Nook HD+ 8.9 inch. While I prefer a smaller screen, I actually found the 8.9 inch screen to still pretty comfortable to read on. And this 8.9 inch tablet is surprisingly light for it's size. And B&N did a great job making this feel comfortable in the hands. The 1280 resolution is very nice as well (note it's a bit wider in portrait mode than most Android tablets). So I agree, it's probably a really good choice right now at only $150.