I have a Calkins trailer that is needing some work on the roller assemblies and rollers. The trailer is used to haul my 19' Seasport Skipper. It is one of these types of trailers that the inside frames pivot up and down as you load the boat. I have looked at replacing the roller assemblies and center rollers and assemblies. I figure to replace them all in will cost well over a grand. My question, on these type of trailers that pivot can you put bunks on them (perhaps in the rear half) or do I need to stick with the rollers. Any other advice on what would be best for this trailer would be appreciated.