Here's some tips How to find music which also applies to video. Some other tips for video: Movie download issues (click on blue link) (2nd last post has information on best video formats.)

I have a suspicion you would be better off with LW 4.16, but that's only IMHO. If you did downgrade back to LW 4.16 you would need to follow the tips as suggested in my very first link in post #2 since both LW 4.18 & 5 use the same location for download preferences. I personally use 4.16 & find it a much more effective version than 4.18, as do many other people.