We continue supplying HP 8000s ink bags even after HP has stopped supporting this printer. It's impossible to buy the original ink cartridges. We are practically the only source of HP8000 inks. Plus, our prices are very reasonable.
Please note that your printer won't be able to show the remaining ink level with these bags. It will still print and it will pause when the ink is out. Don't worry: this won't ruin the print.