if you put better brakes on the truck its just going to make it so the truck can lock up the tires easier... its not going to help it stop. you understand? i have read in the boston whaler forum about a guy who towed a 22ft boat with a cherokee (lord i appologize for that word on this forum <img src="/forums/images/graemlins/lol.gif" alt="" /> ) and when he got on the brakes for a yellow light, his boat pushed his truck (with all 4 tires locked up) right through an intersection... just the momentum of the boat.
id say get one of them electronic brakin systems fo tha trailer this way you can use them to stop the truck.

http://www.easternmarine.com/em_store/trailerbrakes/trailerbrakes_ele.html

http://cgi.ebay.com/ebaymotors/KODI...073QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

keep us posted! <img src="/forums/images/graemlins/cheers.gif" alt="" />