[name]Peter[/name] [name]Nathaniel[/name]: I think this is so handsome! [name]Nathaniel[/name] is a classic name in the Top 100 (it’s also Biblical, as is [name]Nathan[/name]), so this one doesn’t play by your rules. I love it, though!
[name]Peter[/name] [name]Julian[/name] / [name]Peter[/name] [name]Julius[/name]: I love [name]Peter[/name] [name]Julian[/name], but like [name]Nathaniel[/name], it may not be what you’re looking for because of its popularity. I think it’s wonderful, though! To me, [name]Julius[/name] is more distinctive than [name]Julian[/name], if that’s what you’re going for.
[name]Peter[/name] [name]Angelo[/name]: I think this is interesting, in a good way…
[name]Peter[/name] [name]Caspian[/name]: I think this is very handsome, not to mention distinctive.
[name]Peter[/name] [name]Jonas[/name]: I think it’s handsome…
[name]Peter[/name] [name]Charles[/name]: I love this so much, but [name]Charles[/name] is a popular, classic name, so it doesn’t meet your criteria for being unpopular. I think a longer middle sounds great with your last name!
[name]Peter[/name] [name]Albert[/name]: I like some of the others more, but to me, [name]Albert[/name] is distinctive in the middle.
My favorites with your last name, despite their popularity as first names, are [name]Peter[/name] [name]Nathaniel[/name], [name]Peter[/name] [name]Julian[/name].
I also love the sound of [name]Peter[/name] [name]Caspian[/name]!
My all-time favorite [name]Peter[/name] combo in the world is [name]Peter[/name] [name]Sebastian[/name], the amazing name of [name]Susan[/name]'s son. 
More you may like (I’m thinking that your last name rhymes with [name]Cole[/name], but doesn’t start with a K sound…I apologize if I’m wrong):
[name]Peter[/name] [name]Augustin[/name]
[name]Peter[/name] [name]Augustus[/name]
[name]Peter[/name] [name]Elias[/name]
[name]Peter[/name] [name]Harrison[/name]
[name]Peter[/name] [name]Maxfield[/name]
Good luck! 