As a general rule, it's not necessary to post the same question twice in different parts of the forum.
IJM do not sell refillables for a 2100/2200 and have not for many years. This is a very old printer now, and you may still be able to find them online, e.g. from HK suppliers, but it may not be easy. Also, the cartridge designs would be quite old and not as easy to fill or use as the latest designs. If you're talking about a printer for piezography then any of the current piezography inkets would work. You would print with QuadToneRIP and that's certainly still available and supports the 2100/2200, although no new paper curves have been created for a very long time.
I take it from your question that you're not using refillables at present. So you're using OEM carts? What condition is the printer in? Is there a good nozzle check? At the risk of sounding like a broken record, here are some lessons that I've learnt from using refillables that are relevant. My advice FWIW would be not to. I have such a printer downstairs waiting to go to e-waste (along with an R2400 mentioned in another thread today) This printer gave me good service with refillables over a number of years, but eventually the struggle became too much. Hence the lessons.
If you're using refillables successfully now, then by all means give it a try. But if not, then my view is that converting such an old printer now runs too high a risk of failure, for the reasons in my lessons. If you manage to find some refillable carts and decide to give it a try anyway, be sure to follow the printer maintenance instructions first (note that accessing the 2100/2200 wiper blade is different and quite hard to do).
If it were me, if it's working with OEM carts now then I would use QuadToneRIP to print B&W using the K2 QTR curves. I used to do this for a few years and got respectable prints.