I like later more.

The second one with the golden border is more appealling for me

I prefer the former, based on the group shot in your library, squads will stand out on the tabletop. 

Depending on whether they are codex compliant, you could reserve the black pad for Sergeants or other ranks - it does look good with the gold border.

Just my tuppence - both look good!

Rusted Boltgun covered all the thoughts I had. I do feel using one scheme for regular marines and the other for characters or elites would work well and enhance the distinction between the two on the tabletop.

They are definitely not codex compliant.

Still working on the particulars of helmets, Veterans, shoulder trim and whatnot.

Any suggestions are most helpful.

I am going to have the chapter emblem on both shoulders, Black Templar-style. 

If you're using the Maltese cross (i.e., the same cross that the Black Templars use), I recommend the white cross on the black background largely to differentiate them from the Black Templars.

What about Gold and Green?

This way I don't step on the toes of Salamanders or Black Templars.

Gold looks good too.

Do you think about using celtic cross instead of Maltese? It's obviously differentiate your marines from BT and allow you use any shoulderpads colours without confusion

The issue is mass producing a celtic cross across the entire army.

With the cross being green, I've removed the ability to just use the pre-made Black Templar Decals.