New Laptop - which configuration

xiMy

I have been thinking about buying a new ultraportable laptop and found that the Lenovo x220 pretty much satisfies my needs.
What I am not sure about is the configuration.
At the moment the highest I would go is:
PERFORMANCE-SET II MSATA: ThinkPad® University X220 Modell 4290W1B mit 8GB und 120GB OCZ mSATA-SSD
31.8 cm (12.5") HD IPS LED (1366 x 768), Intel® Core™ i5-2520M (2.50 bis 3.20 GHz, 3MB), 320GB + OCZ mSATA-SSD, 8GB, Intel® HD 3000 Grafik shared, Webcam, Bluetooth™ 3.0, DisplayPort, FingerPrint, ohne Betriebssystem
which is at 1150€ and has only 6 cell battery. So i would probably add another 100€ for an additional 9 cell one.

The only thing i would rather not miss is the IPS-Display. (makes i3 impossible)
I could probably live with only 4gb Ram but its only 30-40€ more so ...
I also could save about 180€ on the SSD but I have heard that it gives a nice boost to the system.

Any thoughts about this?
Thanks.


edit:

Maybe I should have added for what I will be using it.
I am in my last bachelor's year in physics.
So it will be lectures, notes, skripts, books
I am using Matlab and at the moment Multisim which I probably will continue to use after the electronics course is finished.