iMac, MB Pro, or Mac Pro?

I am in need of a computer for next semester at Univeristy, Long story short I recently got a ~$500 Win 8 machine and other than the crap crap CRAP OS I'm satisfied with it's capabilities. My plan is to give that Quadcore monster to my dad as he is using a ~15 year old Dell optiplex and I am wanting a Mac as I've heard software/support/build quality wise they're better than Windows ( that and I have a Working PowerMac G3).

I need the computer for Art (digital, and maaaybe a bit of 3D) and for music recording, I also plan to do some gaming on it, not a lot, just maybe casual stuff. Now the question about the mac I have is this: Which one would be better for me to use? an iMac with Iris Pro, the 27" maxed out iMac, The MacbookPro with Iris, a stock MBP with the Nvidia Geforce card, or just a Stock Mac Pro (I think the Mac Pro might just be super overkill). Money is always a concern because I'm used to the Msoft environment (cheaper cost to self build) and I would still need to combine this machine with possible a Wacom Cintiq of some sort in the future.

Also I have an iPad Air so I was wondering if there was even any point in a Laptop mac, as the iPad air is a pretty competent thing and most if not all of it's art apps allow exporting to .PSD, that, and the fact I can do 4k images on the Air is pretty sweet.

The software I plan to use would be my: Paint tool SAI (bootcamp), Adobe Photoshop CS5 Master collection, Maya Studio, Black INK(Bootcamp), any music recording/edit software, Steam(mah games), Corel Painter, as well as Sketchbook Pro and a few other Bootcamp loaded windows art programs.

I use an iMac at work and it seems just like a regular computer to me, and I use my Power Mac G3 at home in combination with a Lenovo K450 with Intel i5, 8Gb DDR3 RAM, 5700Rpm 1Tb HDD, and an Nvidia Geforce GT630. I'm giving the K450 to dad because he can't afford mac anything since he bought that G3 almost 20 years ago and I'm looking for a good replacement as I hate Win8 and work in an environment that really won't let me install a non Genuine version of Win7. I've come to love the layout of OSX and would love it on my windows things..but since it's not possible I beleive a Mac would be a good 5-10 year investment for what I'm doing.