Hi,
To print that long on the 4800 you will need RIP software, the standard Epson software doesn't 'do' prints that long, some 4800's came with RIP software, if you have to buy it it's not cheap but users swear by it.
The 4800 is built like a tank and designed for pro use, so don't worry about it working too hard, it was designed to do exactly that.
Ink...? I'm not sure, I have not experienced that on any of my machines, I do remember though two things happening in the past (though not related to a 4800) one was the Epson software gave me a warning before commencing saying the ink might not complete this print, another time a printer stopped mid print for ink and then carried on seamlessly...
I'd ask an Epson tech about the ink issue...
Best,
Steve