If you want archival quality, stay away from dye-based inks. The ET-7750 uses pigment ink only for the blacks. All colours are dye-based.
I still use an Epson 4800 I bought when they became available on the Swedish market in August 2005. It has been ultra-reliable for these 15 years, partly because I only print on matte papers so I don't have to waste lots of expensive ink switching black inks. I have some prints that have hung on a wall in partial sunlight for over 10 years without fading. These hand-made by one craftsman large format printers are quite expensive, but the hassle-free operation has been worth it for me. With this experience, I would not buy an Epson that doesn't use K3 inks or later inks with similar qualities.
I mostly use Hahnemühle matt papers, either Photo Rag or Photo Matt Fibre. I know how they work and can usually calibrate a new batch using one sheet, cut into smaller sizes to keep time and cost for the calibration down.