「いろんな種類あるんで。」
Is this just an abbreviation of のです？ Or is it supposed to be ので？ I’ve seen んで a handful of times so I thought I would ask about it!
This is just ので, as you surmised. Since the sentence ends there, it probably refers to something the speaker said just before this. Here you could translate the ので/んで kind of like the ", you see." in "There's a wide variety (of goods etc), you see.", although in many contexts this would sound weird in English.
