You do know you can run a Virtual Machine in Windows and install it there virtualized and avoid all the hassle of paid third party software?
Not only is it free, but all you need is an easy to get Windows 7 ISO legally off public internet files.
The MAC can easily run Virtualbox, which , did I mention before its 100% free?
You can literally with those specs run a win7, heck even a win10 image and avoid all the hassles.
Mounting a virtual machine takes at the most, 10 minutes, and mostly while it installs windows off the image.
Once its mounted you can literally run everything there, even install mounting windows software for the client and even run p99 as well without issues within your mac ... for free.
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You can also try to find a fully installed client, which will make your life easier as well, but if you insist on using the game original iso installers think different and just virtualize windows within that puter.
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Mine is a measly core i3 and I can emulate Mac and windows within it without issues.
You can also run wine directly off Mac as well, but thats more complicated, so I believe, the most low tech approach for you is to create a Virtual Machine with Virtualbox and ditch Parallels
Watch this video and tell me if it helps
https://www.youtube.com/watch?v=lEvM-No4eQo
Parallels is just a fancy Virtualbox that will give you tech support that might or might not help.
Give it a try and tell me if it works.
You can ALSO try to see if the Wine experience might work for you as well:
https://www.youtube.com/watch?v=Bz-nI4LW2Jw ... which is free too! 8)