Ok I did a bit of research and 3 brands caught my eye
Apparently, the TSD M3 has a metal outerbarrel and comes with more freebies. Other than that, it's pretty much the same as the other two.
TM shotguns seems to be better, but are more expensive by comparison.
Do you guys have any other inputs or other recommendations?
And please don't argue in this post, I never said anything about double barreled shotguns.