Teak is naturally water resistant, and a natural non skid material, which is why it has been a traditional decking material for many, many, many years. Wood is easy to work with and looks good, even with out any fancy design work. Starboard looks like....well....PLASTIC. It is waterproof, but can get slick when wet. Starboard is very flexible, unless it is very thick. A very thick piece of starboard will most likely cost as much as equivalent teak.
You can rip and join teak with a table saw and a biscuit cutter, then glue it and clamp it 'butcher block' style and it will look great. That is my vote, but it depends on what tools and wood working skills you have.