Hello all cnc gurus !

I'm considering building my own cnc machine. I'm hoping If someone can tell me whether the capabilities Im looking for in a machine are achievable.
I dont have a great deal of knowledge about CNC machines so I apologise in advance If what Im asking is ridiculous !

Id like a cutting area of 700mm x 2000mm.
Id be mainly cutting sheet plastics and wood.
If possible Id like the ability to cut aluminium and hard woods, but that would be a bonus.
Accuracy is very important to me. (+/- 0.1mm ?)
I have a budget of approx £2000.
I have built a 3D printer (Kit from Ultimaker). I have basic welding(mig) and mild steel fabrication skills/tools.
I have very good modelling/CAD skills. I have a pretty accurate FDM 3D printer (Ultimaker2) (max build volume 200mm3)

A little more on what I'm hoping to do with the machine:

Firstly I have some designs Id like to produce large scale stencils for which have some very fine details in. About 0.1mm details to be precise. These details would only need to be cut in a very thin plastic, although I wondered If stacking multiple sheets up and cutting a number at once would be possible.

Id like to be able to cut basics shapes from 18mm ply for furniture design prototypes.

Any advise on whether the above is feasible with this budget would be greatly appreciated.

Jamie