Awesome, I couldn't put my finger on all the different styles but googling your terms got me on the right track. Thanks so much.Technically, loafers shouldn't be worn with suits in the first place. So, all types would be fine for what you're seeking, honestly.
A full strap lofer tends to be the most formal of types, and a half strap loafer would look a little less formal and perhaps hit the sweet spot. A beefroll loafer is usually a little bit more casual.
I wear half strap/pinch penny loafers and beefrolls at work with chinos and a button down.