Prints would be a terrific addition to your shop - do it! :) I've used iprintfromhome and have been very happy with them as well. I do not have any experience with their chromogenic or metallic prints, but I have ordered lustre - it is like semi-gloss but I'd say that the colors are softer. If you want to convo me directly I could send you photos of two prints, one lustre, one matte for comparison.
I don't think you need to have a big supply on hand at this point - I'd just order a few prints to be sure that you have the finish and quality you want, and to photograph them to list.