I'd send it to Mike O and see if he can back bore one barrel and add a perm choke tube to the other. If he can back bore one side .004 to .005 that would give you a decent skeet range choke. If the barrels are thin he might be able to add perm choke tube to both side. I'd let him measure it and give you options.

As to chokes choices it all is personal choices. I've shot I/C to full only chokes for everything. You can change choke effect with different loads, shot, wars or spreaders. But take the easiest route. If you have to special load every shell this gun will not see much use if you have easier options.