Consider DynaStrip
http://www.dynagram.com/
It's a cost-effective standalone PDF based imposition application available for OS X or Windows. Templates are easy to create, whether sheet-fed or multi-web (including partial webs). The jobs are populated with PDF files without any conversion necessary. The resulting PDF impositions are created in seconds and will be easily processed by your existing Harlequin.
If you run an MIS system that creates JDF data, DynaStrip jobs can be created from their stripping parameters. Jobs may also be output as JDF, populated or not, for use with several workflows.
There is also an option to run hot folders, automatically populating plates and outputting them as soon as they are ready. Obviously a popular option for meeting deadlines.
DynaStrip may be purchased as a floating licence, allowing you to connect a hardware key to one computer (where it stays) and then open as many seats as you've purchased anywhere on the network.
DynaStrip is compatible with proxy files from, for example, Digipage — which is a standards-based plug-in for Harlequin which creates EPS files containing the screened 1-bit TIFF files, and both a composite proof and a preview file created from the ripped data — allowing you to impose the actual ripped data; render a preview; print a proof; and finally print back to the rip which needs only stitch together the already screened pages.
http://www.fusionsystems.com/
I hope that helps.
