If your budget is low then buy whats affordable for you. these days almost all laptops run photoshop and illustrator smoothly. Unless you mean running cs5, then you need a more higher processor and mb ram. In the near future ask the school if you get any discount buying a macbook or laptop. Its worth the discount.
I bought ASUS X550CC-XX399 i7-3537U 2.0GHz (dual core), 8GB of RAM (it’s maximum) nVidia GeForce GT 720M 15.6’’ LED 1366×768 4 cell battery, 2.4kg
And I’m pretty happy with it. Display isn’t really great, but I’m using my monitor when working so it’s okay. Performances are great, but the spacebar is quite f*cked up, I’ll need to take care of that.
Thank you everyone for helping! Hope the next one will be macbook