After doing some checking around, I finally decided on Tops in Quality. Nobody could match or come close to their price, and a number of others have recommended them as well. (I'll be happy to fill in the gory details if anyone wants them.)

I had them add an arch, which they did for an additional $25. Here's a snippet of an email to them:
Additional considerations:
1. Please make it look as much like the attached picture of Sirocco as possible (i.e. slight arch/bend going up to AND over taff rail - following the lines of the transom)
I don't know that they actually read the emails, but when all was said and done, I'm pretty pleased.