Ck out this tower I built over the winter. I have a 95 bayliner 2050 with a 4.3l... Does a good job for starting out. About 600.00 into it. I make the racks out of 1/2 inch plate aluminume, had them cut at a shop then sanded and polished them. Speakers I made out of pvc tube 6 inch and glued cap on them, painted and installed speakers, clamps off ebay for 50.00, total in speakers and racks 325.00.
Had lesman iron bend the arch with their roller, bent the 90 with a exhaust bender at my buddies shop. Its 2 inch aluminum for the tower and I used exhaust tubing for the part that attaches to the boat for cost and streangth.
Scott, nice work there. Did you powder coat it or paint it? Looks very nice. The racks are very impressive also. When I built my first speakers cans out of PVC, I thought about adding the smaller tube for a tweeter and getting component speakers also. That set up turned out very nice.