The major difference between bunks and rollers is the way you load and unload the boat.
Rollers allow you to drive on and off in shallow water.
Bunks require you to float the boat on and off, and you need deeper water so the boat floats off the bunks.
IF your local ramps are shallow you will want to keep the rollers. BassPro sells a pair of rollers, (5' long) for less than $200.
IF the budget doesnt allow the new rollers, and you have shallow ramps, use the glide sticks. Actually the material is cutting board material. HDPE- High density polyethelene. Might be chaper to buy a large cutting board and cut it up into 1 1/2" strips to put ont eh carpeted bunks. Careful the boat will act like its on rollers, and there are stories of guys dropping thier boats on the ramp before they get it in the water. Typically they stop suddenly, and it slides off. LEave the winch strap on until the last minute, just to be safe.
As for your side guides chewing up the boat, use some of the HDPE on the uprights.