Get 1 or 2. Unless you're working in Alaska or have to bond together speakers being crushed by a semi, T3 is a complete waste of money. I use T1 and T2 regularly, the only difference being how much time I have: T1 dries faster and sands easier, T2 is a better bond and dries aesthetically clearer. Both bond stronger than wood, and I've run enclosures for 3 18s with T1 and enclosures for 1 3" driver with T3 so it all depends on the environment and your time, not the application.