I would recommend a Parke Merkelo 660 rim-285 depth or 660 rim -290 depth.
They have recently expanded/updated the mouthpiecerentals.com with approximate rim sizes and depths in the left side.
Parke is not making any custom mouthpieces at this time. They are just manufacturing parts (rims, cups, backbores, tops, and a few one piece mouthpieces) in the most requested sizes. i enquired earlier this year about a custom mouthpiece, even using stock specs, they are not making them right now.
I am currently playing on a Parke Merkelo 630-275-24 for most applications. I also have a 285 cup and 260 cup.
If you have any questions, you should just ask them. They are very good a responding to any questions or give you some recommendations.
customerservice@mouthpiecerentals.com
Unless you know what you are looking for, the new website is a little hard to manage. There are no charts, or size comparisons, and nothing written about the models.