Turf and carpet is pretty much a waste of time and money. Some carpets may work better than others, but you have to use a shitload of water and soap to make them slide; then when you hop onto a PVC rail with soap on the bottom of your skis, it can be too slick.
The best stuff I have seen for drop ins is plastic lattice fencing sold at Home Depot. They sell it in 4 x 8 and 2 x 8. You can screw it directly to your frame so you really don't even need to buy plywood. You don't need to use water on this stuff. For the jump, construction fence on top of dirt with a layer of plastic in between like lawn and leaf bags. That keeps the dirt from getting on the top side of the fencing. For the ski out, construction fence works great. If you're putting it on top of dirt, put plastic down.