Replacing a 15R 5520 Motherboard for 15R 7520 MotherBoard

I'm trying to be a bit cost effective for college by replacing parts of an old computer in order to get it to run CAD (specifically making it possible to run Solidworks 2016) better, but I am new to modifying computers. I currently have a Dell 15r 5520 with no modifications. I have found a 15R 7520 motherboard on eBay to replace it but it says with no video. Does this mean I would have to buy a separate graphics card? If so, any recommendations? Would I be correct in assuming that it comes with the i7 processor? Also any input on upgrading to a SSD?