Try Lumber Liquidators for teak.They stock 3/4"X3-1/4 and 3/4"X5" teak flooring in a few shades.It may work good for your use.If I remember right,The teak stips on my Tsunami that cover the seams like in your picture are strips about 1/2" or 3'4" thick.
http://www.lumberliquidators.com/ll/...z13z24/Ne-lfma