Thanks again for your input and links.
I agree that a dedicated Wave editor should be better, but I can't imagine there would be too much of a time-saving as I can do everything you mentioned in Vegas Pro, working directly with the audio in the video file.
I can zoom in to sample accuracy, normalise and export as WAV, MP3 or whatever. I also have the visual reference of whatever it is making the sound, so I can name the samples appropriately and use the video clip in my final production. It sounds obvious, but when I'm sampling the sound of a box cutter, ripping plastic or a barbell dropping on the floor, you can see that they are not typical musical/percussion sounds!
I just re-read my OP and I wasn't precise enough about my aims.
My question has more to do with collecting all the samples together, making some kind of patch or kit, and then the most effective way to play them from my keyboard in a musical piece.
Your suggestion of Session Drummer and/or abacab's Battery idea, seem to be the way to go.
FYI: I use Xilisoft Video Converter Ultimate to batch convert video and audio, it's very simple and versatile. http://www.xilisoft.com/video-converter.html
Thanks again,