Clearly, you need to create a realistic budget. If you can dream it, you can probably find the materials and the plan to build it. But, the most important factor is cost. Can you afford to build the out deck of your dreams or do you need to scale your plans back a bit in order to make your deck affordable?
Try locating suppliers on the manufacturers website or search your local builder's store inventory to see what is available and how expensive it is. Keep in mind that composite material can be three times the price of wood. However, consider the time saving factor and expense of staining your deck every year. Cost eventually evens out and you have actually saved yourself some of the extra added maintenance associated with a real wood option.