I think either are beautiful, but I picked Penelope because I think it sounds really good with your last name. BUT she might change it someday when she's married anyhow. You can't go wrong either way!
I voted for Penelope because it's different, but I think Isabella flows better with your last name. @ramstein1027 has a point that she may change her last name one day.
I picked Aria Isabella because I like that they both end with an A. Also I did the yell test. You test out the name by yelling it and then saying, "Pick up your toys." Which ever one feels better to you is the one you pick.
It's such a hard decision! Even with the yell test, I think both sound good. H has always like Penelope, but I wasn't open to it until recently. Everyone that we've asked has said Aria Isabella is really pretty and only a few have like Aria Penelope. I know it's our decision, but it's hard to not take other opinions into consideration.
Re: Which middle name do you like better?