Have you considered a used HP Latex machine with a separate cutter. Prints come off dry, the media isnt expensive like your aqueous set up. The print is fairly robust. Some good deals on second user 26500 and 25500 machines (dealer supplied with some warranty) You can find 3rd party inks for it. If you are going to invest in kit then you also want to bring your production cost per unit down as well as be able to increase production etc.
I have not actually looked into latex, is it very fiddly? For ease of use is it comparable to solvent? Are the prints more durable than solvent if they're not laminated?