I'm assuming you're looking at notebooks. Visual Studio runs fine in a VM, at least for smaller projects. I haven't tried it with anything enormous, but you shouldn't run into any troubles. It's not like your CS homework will be tens of thousands of lines or more. If it's game development, there will probably be some DirectX work. As long as it supports the latest directX you're probably fine. While discrete graphics will help if they have you working with Maya, Houdini, or other 3D apps on something non-trivial (really I have no idea about the scope) you will probably want to use the machines at their labs, as they are likely to be significantly smoother for that kind of work under Windows. Mac gpu options are a bit hit and miss there.
If you're looking at game development, start learning maya or 3ds max early on. Your college will probably use one or the other, but once you know one it's easy to switch. If you're primarily using OSX, it will be maya. It has a lot of quirks, so it will take time to get completely used to it. A couple examples that get beginners would be that tweak nodes (vertex tweaking) commonly break construction history, and if you extend something via extrusion, you have to ensure that you weld all of the vertices. You can get a free student license if you sign up on Autodesk.
I completely understand only wanting to buy what you need. You shouldn't need anything too heavy, and I would caution against over-spending. Sometimes your needs change or something happens to your machine. Within a given line of notebooks, I find most upgrades don't extend the life of the system by much. Even in integrated vs discrete graphics, the discrete graphics available on notebooks aren't very close to what you can get in a desktop or workstation.