Calendar with 2 alarms for each event

For the same time and date? Combine the two sounds you want in a sound editor (like Audacity) and use that as the alert.

 

maybe he wants an alarm 15 minutes prior and an alarm on-time?

 

DigiCal allows you to easily add many reminders to an event.

 

Unless you want or need another calendar on your device, why not just create two (or more) events for the same date/time with different reminder times. It's easy to do and it does the job.