The Pro and the Pro-X1 are the same, except for spacing. Since you'll want a 3/16" board spacing when the deck is finished, the Pro provides that at installation. The Pro-X1's narrower 1/16" spacing is made for boards that will shrink a significant amount after installation (such as pressure-treated lumber). The end result will be a properly spaced deck.
The third Marksman Pro, the Pro-NB, is made for decks using narrow boards.
Should I get ProTech Coated or Stainless Steel screws?
CAMO's ProTech coating will likely meet your needs. It is formulated for use with ACQ (Alkaline Copper Quaternary) lumber, which can handle high exposure to the elements, and is resistant to biological elements like bacteria and fungus.
Although a more expensive option, Stainless Steel does offer the most protection against corrosion if your deck is located in a marine or coastal environment.
Which Torx drive screwdriver bit do I need?
You will most likely be using the regular driver bit (Do it Best item # 239423). One is included in every container of CAMO fasteners. The Grooved Board bit is only needed if you are using grooved deck boards. You can buy the Grooved Board bits - or extra regular driver bits - below.
Note: each package comes with two drive bits.
Will it void my deckboard manufacturer's warranty if I don't use their fasteners?
CAMO has you covered! The CAMO warranty covers those manufacturers' deck boards, including wood alternatives like composite, capstock, and PVC decking products. CAMO's coverage is the best in the business. You can read their warranty specifics here.