After bothering for a long time I spent the money! I come from the Netherlands, and make most movies of our kennel. It's not profi yet, but I am ready to take the next step. I see progression in my work. (can find the movies here http://www.redfairytales.nl/index.php?option=com_content&task=category&sectionid=6&id=33&Itemid=70&lang=en)

My question:
- do you use a UV-filter as protection on your cam 72mm? and what kind?
- what kind of external microphone should I buy? I saw de Rode videomic (cheap) and the AudioTechnica AT835ST (expensive)

Yes, I definately use a filter as a protective device on that expensive lens. I always have since the 70's when I was shooting stills with my old Nikons. It's a good habit to get into, especially if you shoot outdoors a lot.
Mic selection depends on your application. For interviews, I use a Sennheiser EW112-G2, general use, I also have a AT822, and those two cover my needs for the time being.