iBooks vs. Kindle - Which is better for a theological library?

I have been considering investing in digital books instead of physical books as I continue to build a library of books for ministry. The question that I have for you is: Apple's iBooks or Amazon.com's Kindle. Here is what I have so far:
Kindle - Pro
Larger selection of books
Books are key component to Amazon.com's business strategy
Multi platform reader (mobile device, Kindle, computer)
Page numbers match the physical book
Kindle - Con
Black and White books
A Kindle has a single use.
iBooks - Pro
Color books
An iPad has multiple uses
Reader is available only limited devices
Integrated into a device that I already own (iPhone)
I am generally a fan of Apple
iBooks - Con
Smaller selection of books
Books seem to be outside of Apple's core product strategy
What other pros and cons have I missed? Have you used these platforms? Which do you recommend?
