My first thought was also to buy a Sintratec SLS machine as it opens up many new possibilities and with different powders you can print various materials.
A ceramic bead polisher is not extremely expensive to smoothen your parts.
The MCOR machines feel a bit low-tech and crafty to me, I see some use for it business-wise but it's not my cup of tea. Colors are a bit faded, you are limited to one type of material that is mechanically strong but otherwise not very interesting, and it is slow.
I would consider buying different DIY machines - a desktop CNC mill/cutter/engraver and a small injection molding machine for example.