Thanks for all the answers!
BTW … I didn't get the printer for sign work. I also got it for a steal!
Welcome to the forum, hopefully you didn't pay much because the 9900s are a generation old, we had 4 at one point and ended up giving them away since they have little value with Epson's new printers (Surecolor P9000/P10000/P20000). It doesn't really matter what you paid for it because the 9900s were great printers and a good value at their regular retail price so it's likely you got a fair price.
The SP9900 served two main markets: Photo printing and Proofing for screen/offset/litho/etc. We used them for art decor printing, but we also were able to buy pressure sensitive vinyl and laminate to create prints that could go out doors for several years (but rarely did this as we also have UV, Eco Solvent, and latex printers). If you put a laminate on your prints you could very well produce roll up banners (assuming you find a non curl polyester aqueous printable material), and since foam core and gator foam are indoor materials I don't see why you couldn't sell mounted prints to both materials (don't try to compete on pricing for foam core/gator prints with online companies as they will direct print and that process is a fraction of the cost that your process will end up being).
To answer your question though of if a different type of printer is better for producing gator foam or foam core prints - that depends on the application. If it's a sign than yes those printer types might be better, but if it's a mounted photo print than no, your printer would be most likely be a better printer. And going even more in depth, if you are trying to make signs than a UV printer would be the best method because even though UV image quality is lower than Solvent/Latex, most Uv printers today have decent to good image quality and are cheaper/faster/more durable without laminating when making signs.
Best of luck and again, welcome to the forum!
