I would go for the Boston if i was you because it is made for what you are requesting. Yet both are pretty silly machines. You will most likely end up needing more SSD space but they are easy to install.
You will end up more or less getting what you pay for with these. It is up to you what you want the most function or design.
There is not a huge difference between to two machine you mention.
Congratulation on your new computer whatever you may choice.
I cannot do that as I have never tried Mac for 3D work. I can only say part of what you buy is the image of the product. So as hardware goes you do not get as much for the buck.
The quadro series from nividia are made for graphical work and the Radeon is like the Geforce.
I have not looked in the greater detail on the spec but all the components need to be in equal strength.
That is why i would pick the pc but i still don't think there is gonna be a noticeable difference between the two.