You can use camper tiedown turnbuckles attatched to the frame of the trailer. Weld some tabs with holes if you want to. There is a really good topic several pages long with LOTS of pics of truck campers on gooseneck trailers here on this forum.
You can read THIS one about truck campers on flatbed trucks for some ideas. I am searching for the gooseneck trailers topic now.
EDIT: And HERE it is, truck campers on gooseneck trailers discussion.
* This post was
edited 07/26/08 03:43pm by SoCalDesertRider *