I use Serif MoviePlus 5 available at serif.com. Although you will get an american website the company is based in Nottingham. It allows multiple timelines for both video and audio. You will however need to consider what format your data is in; if it is analogue there will be problems with dropped frames but they do an adaptor (Grabbee) that works well for me. Give them a call on (0800 376 7070) and if you are interested try haggling for a free trial of MoviePlus doesn't have all the bells and whistles but it will give you a fair idea if it's whwt you want.