there is a third.... http://www.bhphotovideo.com/bnh/controller/home?O=details_accessories&A=details&Q=&sku=355585&is=REG
This is a .8 from Sony's Z1U HDV camcorder...it works great on the DVX100a. I own it and use it all the time. A .6 is wider than a .8 BUT it cost quite a bit more as well. Be sure that the .6 you get is a zoom through...a non zoom through costs less but has limitations of zooming. I also own a .6 non zoom from Century, it's been good, but I should have spent more up front and gotten the zoom through version. Also a sunsahde for the Century will cost you. The Sony .8 will run you about $400 and comes with a sun shade. Also...look into a lens from 16x9inc.com
I understand that those accept filters.
I will soon be recieving a .5x red eye wide angle adapter made by collinscraft. I believe the owner of that company surfs the board here with the name red_eye_guy. I'll post some grabs as soon as I get it.