Need help deciding if a surface is right for me.

So currently I am a student away at college. With me I have a first gen ipad mini and a late 2012 27" iMac (i7, 8GB, 1TB hybrid, 2GB graphics).

Recently I have been noticing my desire to have a portable computing machine. Whether it be for travel, quick trips back home, in class notes, or library work sessions. My mini isn't cutting it and my imac is stuck in my dorm. Not to mention, for some reason my iMac seems to be so slow. It boots up slow for an ssd, photoshop can be a hassle, same with opening final cut, etc..

So I need some advice on what path I should take. So here is what I've been thinking.

I was considering buying a decently powerful Retina MBP. Using it as my main machine and eventually selling my iMac. Could I get one that could handle PS, Video editing, audacity, etc for around 1200?

The second option was get the Surface Pro 4. I would get the i5 8GB of ram version. This is where i've been leaning because of how cool it seems. I'm just concerned about its longevity and switching to windows. I haven't decided if I would keep my iMac in this situation.

My other two options are to get either a newer ipad with a typing cover and keep the iMac, or get a cheaper laptop (like a macbook air) and keep the imac.

My biggest concerns about the Surface are 1. switching from OSX to Window's since I have Photoshop on OSX. 2. Build quality of the surface. 3. I see a lot of people complaining about the reliability and issues with the surface.

Any advice?