CAL SIGHTING>>>>
Cal, whatever you do, make sure the bunks are fit just perfectly - I've heard that ill-fitting bunks cause permanent hull problems.
If I was building a dream trailer, it would have at the minimum: oil-bath hubs, two spares tires with hard covers like the Rav4 spare, a lockable box for trailer tools, two spare hubs, transome straps, 12vdc air pump, etc. I'd want a totally overkilled tongue jack that just doesn't wobble at all. Speaking of tongue weight, it'd be nice to get the balance correct finally. Maybe even have some nice rings on the trailer made for attaching boat cover straps.
Anything else? How 'bout Line-X the steps?