After looking over a list of materials and taking a serious inventory of your fiberglassing or sewing skills and color sense, you may actually be able to build a decent hardtop or bimini soft top for your boat more cheaply, with a better fit and--possibly--more cheaply than you can buy and install a ready-made top.
A hardtop for a boat is like the hardtop for a car; its made from the same type of material as your boat and isn't flexible. It has to be "removed" while ashore, since it can't be carried with you.
Fiberglass both sides and all the edges of a sheet, or sheets, of marine plywood by applying epoxy. Lay sheets of fiberglass cloth onto the resin, pressing the cloth down into the resin with a putty knife. When the resin cures, sand the fiberglass and resin with 220-grit sandpaper and repeat the process. Fiberglass both the top and bottom of the plywood, and around the edges, laying on several layers of fiberglass until you have a "fiberglass sandwich" with a fiberglass outside and a marine plywood core.
After you've made your "sandwich," you can make supports to hold it up, out of PVC or aluminum tubing, anchored to your deck with commercially-available mounting brackets or brackets you fabricate.
A bimini top is a canvas canopy, stretched over an upper support frame, which is then supported above your deck. You can make the frames by joining 1-inch aluminum or PVC pipes or tubing together with "T" joints.
Attach snaps to the edges of the canvas you plan to use for the canopy and you can roll the edge of the canvas over the pipes and snap the canopy in place.
The canopy material can be natural cotton canvas or it can be one of the new synthetics that resist mold and mildew. As with the hardtop, you can use commercially-available mounts or homemade mounts to hold PVC or aluminum "legs" to your deck or sides. The commercially made mounts have an advantage: they can fold down, meaning you have a convertible top for your boat.
Anchoring the Top to Your Boat
Commercially-made mounts to attach the top to your boat fasten to the gunwales (the top of the sides of your boat), the rails of your boat or the deck of your boat with a few screws and a screwdriver. After they're attached, you only need to slip the support posts into them.
Homemade mounts can be made from a small piece of PVC pipe, with an inside diameter (ID) slightly larger than the support posts. Cut a piece of pipe with an ID that's 1/8 inch larger than your support posts and at least 3 inches long. Paint the pipe segment yellow. Drill a 1/2 inch hole through one side of this small pipe segment. Attach one end of the pipe segment to the deck with epoxy adhesive sealant. Slip the support pipe into the pipe segment and screw a #14 wood screw, 1 inch in length, into the hole you drilled in the side of the pipe segment, to hold the support pipe in place.
- Fiberglass Boat image by Wimbledon from Fotolia.com