Hey Bob,
Many printers can be converted to use dye sub inks. There are bulk ink systems as well as close cart systems, both typically sold by sawgrass.
Whatever printer you decide on, you will pretty much only be able to use that printer for dye sub inks. Its a real pain to go back.
But lets say you have a printer setup and ready to go for sublimation purposes. Once you print an image using dye sub inks, you should press it that same day. I would not recommend pressing much more than 48 hours have went by. When I was starting out I tried to press some old prints I made a week ago, the transfer did not come out clean at all and it had bad color and a bunch of small color voids.
Once you get beyond the 48 hour window I would assume that even though you will get a clean transfer into the metal, the colors might be a bit off so you might have to have a custom profile built for that.
If I were you and were serious about doing this. I would wait until later this year. Right now sawgrass owns the patent on dye sub inks and its really expensive. Their patent expires at the end of this year and that should open the door for competition which will bring a decrease in pricing for sublimation inks.