ActivePDF is probably the most sophisticated,scalable, reliable and stable solution but it's also rather pricey. It works through a printer driver as well but also provides a rich PDF API.

It supports creating multiple reports at the same time and has upgrades to allow multi-processor versions to server PDF ifle. Install the product and then use the wwActivePDF class - make sure you match the intalled ActivePDF printer name to the cPrinterDriver property.

Active PDF Site
Price: ($499 - $799 versions)