I've never actually made a print of a digital photo. I only have developed copies of 35mm and 6x6mm film. What type of digital printing is best for long-lasting colors?
Setting up your own printer is quite expensive but you would get enormous enjoyment from printing and enjoying the results of your labours.
If you are only going to make prints occasionally, it is more economical to send the files to one of the many services that will make prints and mail the finished results to you. What you are looking for is a company which uses giclée (inkjet) printers with more than the four basic inks.
Pigment inks offer longer print-life than dye-based inks so choose a company that has that kind of printer if you can.
You need to send them images which have 300 pixels psi (often wrongly called "DPI"!) meaning 300 pixels per sq. inch.
Your local guys probably use metric so that equals approximately 120 pixels per sq. cm..
Hope this helps!