I prefer the goal post style because in addition to centering the boat when loading, they make it easy to see the empty trailer when backing down the ramp.  The side bunk variety are too low to see when i tow with my pickup and depending on how steep the ramp is, may actually be under water when loading the boat.

The only real tip is to make sure that the tops of the goal post are long enough to be above the boat's rub rail when loading with the trailer in the water.  If not, it is possible for the top of the goal post to scratch the side of the boat and catch under the rub rail as the boat comes out of the water.  I learned that lesson the hard way with my Nimble Arctic.  It is easy enough to lengthen the goal posts by buying the appropriate diameter PVC pipe at HD.

I agree...the “goal post” style work extremely well with my Peeler. Launching, visibility of the trailer when backing, and alignment when retrieving.  The kits are very easy to source and should include galvanized brackets, bolts, and 2” pvc pipes.  As mentioned, the pipes are easily replaced if damaged or you decide on a custom length 

Mike

the goal post guides are the standard here.  Very normal for  center console bay boats, ski boats and other salt water boats boats.    A trailer without them is just not right.  Some get sofisticated and mount the lights on the top of the poles to prevent corrosion.  Of course they do not mount the lights on rotating parts.