I'm looking at getting the LetusHD100 for my JVC, I don't own any 35mm lenses, so before I can specify what kind of mount I want I need to decide on which typle of lenses I should use, Nikon or Canon? Also if for example I were to choose Canon, I know there are different lines of Canon lenses, for example EOS, will I be able to use EOS lenses or only a certain class of lenses, same for Nikon as well? Thanks.

you cant use eos.. (as long as there hasnt been a change during my 2 month absence from the forum) only fd and nikon. with the letus you get both mounts so you can invest in both lenses. i started out with fd and changed to older style nikkor lenses. I find the make is much sturdier.. the lenses are nice and heavy and just feel alot better to me.. and im a huge canon fan.. xl2 and a 30d.. also with nikkor lenses its easier to stop down the lens without having to rig them up.