Advice & thoughts please on this 5-axis design

[Plaxton]

I'd like some advice please on the merits (or otherwise) of a 5-axis machine of the design shown below;

I'm completely new to the world of CNC (although have used 2D plotters & cutters extensively) and am considering building (or buying) something along these lines for machining medium-sized (max 1m x 1m x 250mm) shapes out of rigid foam and machinable wax. I'm sure what I really want is a rotating head machine but other than things like the 5axismaker these just don't seem to exist for the home/small business user, which is something I don't really understand.

The nature (size and bulk) of the things I want to machine don't lend themselves to a tilting-bed type machine, so I've come up with the design shown below which (it seems to me) would be fairly straightforward to build using off-the-shelf components. BUT I have no idea about whether a machine like this could be controlled & programmed using regular CNC software - specifically whether, instead of having a fixed vertical spindle, having the entire spindle body rotate either in the Y-plane (as shown) or in the X-plane (which would work just as well) is something standard software could handle. Any advice regarding this would be gratefully received - I suspect and hope the answer is "Yes" because I know that (for instance) Mach3 can drive all sorts of different types of machine, but I'm still at the bottom of a steep learning curve with this stuff and haven't yet come across anything exactly comparable to this.

Thanks in advance for any comments, and feel free to point-out any other major flaws in what I'm trying to do that I probably haven't even thought of!

<img src="https://magazineexchange.co.uk/cw/MagEx_Design/5-axis-design.jpg">