Somebody there doesn't know what they are talking about, you should have BOTH a safety chain to keep the boat from sliding back if the winch fails, and a tie down in the front to keep the bow from bouncing up and down in the bow stop. If you want to talk to people who REALLY know about trailers go over to:
http://www.championtrailers.comI rebuilt my old 1994 Load Rite with their help and
http://www.trailerpartsdepot.com as well as
http://www.easternmarine.com Eastern Marine has good prices on Kodiak disc brakes, as does Champion. Eastern also sells one of the better trailer tire brands (Loadstar).
Champion built a new axle to my specs and I added their brake kit. Trailer parts depot sells OE Load Rite parts so I was able to replace the rollar bars with longer ones and put on a longer tongue.
Chamnpion also sell a set up to mount a chain and turnbuckle on the trailer tongue to act as a tiedown, very heavy duty, instead of the typical straps. They sell all kinds of parts for the do it yourselfer so you can custom build your trailer the way you want it.
They do sell really nice all aluminum bunk trailers but don't ship, you have to drive to La to get one!
Here we have to use rollers because of the tidal change being 7 feet between high and low, a bunk would never work at low tide, even with a longer tongue.