These digicams will never give you great sound, even the ones that claim to record in 5.1 sound.
You can pick up a HV20 for around £350 from ebay or order direct from Japan
www.pricejapan.com for even less. Personally I'd order one from the US for the same price but you'll have to find a retailer that ships abroad.
I think recording to tape is the way to go, much better than SSD or similiar technology. You'll gain the fastest possible video bitrates using tape technology, plus you'll always have the master as the backup. Editing is also much easier with tape based devices.
Check out the Sony HC7 as well.