Yoga 2 Pro/X1 Carbon/X240

1) What is your budget?

So my Lenovo X220T need MOBO replacement and Lenovo couldnt find one so they offered this: or equivalent laptop as replacement.
Amazon.com: Lenovo ThinkPad X240 20AL008JUS 13-Inch LED Touch-Screen Ultrabook (1.9GHz Intel Core i5-4300U processor, 4 GB RAM, 500 GB 7200 HDD, Win 8 Pro-64 ): Computers & Accessories
On lenovo site the same spec is 1350 basically

So I basically came up with 3 options that cost essentially the same.

2) What size notebook would you prefer?

Yoga 2 Pro-I7 8gb ram, medium screen medium battery 240ssd
X1 Carbon-I5 4gb ram, largest screen shortest battery 120ssd
X240-i5 4gb ram HDD, but I can pull my SSD from my X220 and upgrade the ram myself. smallest screen and longest battery life (especially if I can swing a 6 cell instead).

6) What are the primary tasks will you be performing with this notebook?

School

7) Will you be taking the notebook with you to different places, leaving it on your desk or both?

Take it around

8) Will you be playing games on your notebook? If so, please state which games or types of games?

No

9) How many hours of battery life do you need?

Not sure

Unique Considerations

I got a Desktop that is very good. It seems like Yoga 2 Pro is a winner overall (versatile, thin, good screen, better spec) but with 2 major draw backs...
I have a 27in screen with 2560x1440 that the Yoga 2 Pro will not be able to use.
It is not a THINKPAD I am pretty tough with my notebook....and I dont think the customer service would be as good (maybe I cant even purchase onsite warrenty? )