I haven't heard of a Bersa 380 Plus. I guess it's how the 380 Super is branded in the USA.
If that's the case, you won't find much difference between them. The frame is the same and the Super/Plus is wider but I don't think is more than a tenth of an inch. The magazine release is in a different position (above the trigger in the regular 380 and below (1911 style) in the Super/Plus).
I'm not sure if you can get the matte/gold version of the Super/Plus of the shelf. As far as I know, it was a limited edition for the 380 only. You can send the parts to be gold plated though.
I don't know about prices in the USA. Here in Argentina there's not much difference between 380 models. About 50-60 dollars from the cheapest to the more expensive.
Maybe you'd like to take a look at the 380CC (concealed carry). It's a slimmer version of the regular 380 and it's 8+1.