Getting a portable Mac that can mix:which one for my needs?

So many questions, so many things to consider, I need a portable Mac which can also mix. I now have a 2006 Mac Pro with pro tools 9.0.2 and I'm still fine with it. I use 96k (don't ask I wouldn't go there, let's say to me it sounds better, also plugs sound much better). I have two LIOs which I primarily use for mixing and I use other plugs like lexicon, soundtoys, and other stuff... I do automations, I work most of the time with buffer at 128 for production and I like to keep it low as much as I can for mixing. My system is very well optimized (more than avid recommendations, meaning I killed all process or even removed part of the system, that's not needed for audio) and it is snappy and doesn't crash.



I'm considering MacBook Pros and iMacs...



Point is I need to consider all this in the long run. I don't want it to become obsolete fast and I have very little money to spend... In a future, as distant as I can, I'll buy a new Mac Pro to use in the studio, but I'll still need to use this portable rig in location... And for now (and as much as it'll last, I would use that one for mixing instead my old Mac pro... If it can handle it)



Questions are dual core, quad core, i5 or i7? How much these things affect my way of working?



I don't use VI, even though certain like diva, ace and few other stuff, sound pleasant to my ears, and would be good to use them sometimes... Even though I don't really know how much in practice because I do have real things which I prefer all the time (MPC60, s900, s1100, Juno 60, ms20, cs15, tx81z, nord rack2x, microkorg, sk1, not much stuff but all better sounding or have more personality than plugs)



I read dual core i5 do hyper threading, quad don't... Seems I don't have the money for a quad i7... Cause the only one would have been the mini, but it has been discontinued... And also 2.3 quad i7 seems less performing than a 2.6 or higher i5 dual core, in single core performances... And I read clock matters more than core for audio...



Most thing I use are real time processing, I'm a real time lover... And I use convolution reverbs just few times...



So, all these things considered, would a MacBook Pro (retina?) be good for me? Or better an iMac i5 quad...? Or an old Mac mini 2.3 quad...? Or should I look for a used 2011, 2012 MacBook Pro with a quad i7?... Or a used iMac with quad i7



Ideally I would have two drives one for the os one for recording (ideally 4, as I think one of the reasons my Mac Pro is still so performing is because I have one for os one for recording, one for samples, one for all the rest... But that's even less possible today, and I'm not using sw samplers anymore... So... Not so important)



Another thing to consider is the new MacBook retina ship with ssd, while with iMacs I would have to change the hd... And I already have an ssd to put in there, but they are a big pain to open compared to 2011 iMacs



So... What would you do

If you were me?



Thanks

Getting a portable Mac that can mix:which one for my needs?