I'm looking for opinions/ideas/suggestions about small boat trailers.

Some years ago I had a 3.4m daysailer dinghy which came with a "combi-trailer" comprising a road trailer and accompanying launching trolley, which locked onto the trailer. The idea being that only the launching trolley, which was a simple device without proper wheel bearings etc, went into the water for launch and recovery.

I'm currently looking at options for another dinghy, but most of the manufacturer-supplied trailers appear to be one-piece so the entire unit will end up in the water. I'm concerned about what this will mean in terms of corrosion etc, especially with salt water and how this will affect the trailer. Even if the trailer is conscientiously hosed down after use I can't believe there will be no salt remaining. The experience of those who have used one-piece trailer/launchers would be of value.

If I do decide I should stay with a combi type trailer I suppose one option is to forgo the manufacturer's offering and get a comb-trailer made. If I go that route then recommendations for a reputable supplier (Sydney region) would be appreciated.