If you want to see a picture, click this link: http://www.davidanders.com/charmed_01.html. Warning! Pictures may cause laughter! Also, if you want to hear his original accent, listen carefully when Sark talks in the episode Crossings. He pretends to be a CIA officer from Portland OR (which is where DA's from).
I've watched the Charmed episode where David was on. Seriously, it was totally weird seeing him with a moustache (and a pretty thick one too! :lol and he doesn't look great with one, that's for sure! One thing to mention also is his hair - definitely not Sark's style! I think he has an English accent too on that epi. ^_^