Summary Customer Aging Reports

I am new to jet reports. I found an aging report which runs all detailed open transactions for customers, which then summarises for each customer. By hiding the individual invoice lines, it give a very good summary report.

However, the volume of open items means the report takes 10-15 mins to run each time, and is difficult to sort on summary.

I would like to get a report which returns only the summary information, which can then be sorted. I relaise the aging claucaltions maye be difficult if only total amounts are pulled in. Alternatively I would like the report to sort alphabetically as it runs but this is very very slow if pulling back all ideas.

Anyone come accross such a summary report?

Let me know , thanks.

;)