I haven't seen it all by far, but all the LA roller motors I've seen so far have had long nose cams, even if they didn't have the eccentric on them. They just used a cam thrust washer with a deeper cup with no eccentric.
The short nose cams are for Magnums, and even though they will fit and work in a roller LA, if you select one of those you have to keep in mind that the Magnum cam specs are based on their 1.7:1 rocker ratio and will be considerably tamer when paired with the LA's 1.6:1 rockers.