Provide expertise on smoothly delivering audio and video to a website, cross-browser, including iPad

I'm a web developer who needs audio/video expertise in delivering video and audio as flawlessly as possible via the web. It must all work cross-browser including iPad / iPod / iPhone. My client only wants to deliver MP4 and MP3.

Currently, it all works but:

(i) Video stalls and crashes on iPad due to buffering problems - my client only has MP4 available and I'm delivering it via a Flash player and HTML5;

(ii) Audio has to load completely before the audio controls show resulting in an unacceptable delay before anything happens. The client only has MP3 available and again I'm delivering it via HTML5 and a flash player. Putting up a "Loading..." message is not an option unless I can get reliable cross-browser access to a "loaded" event from the audio player / browser.

The client cannot/will not create other types of a/v (only MP4/MP3) and they want to deliver a/v to people who will be very unforgiving because they will be paying for it. I need a quick turnaround on this. Thanks to anyone who can help!

I estimate the job will take you no more than two hrs because I'm probably able to do all the implementation, I just need you to tell me what to do, though I guess we might have to try a few things.