I'm hearing some people are having trouble finding the bidirectional tape at their local stores. Here is a link to mail order it. I bought a couple of rolls of the 2" reinforced tape and it is enough to do at least 4 Assassins per roll.
Or here if you want to build a lot of planes
I have heard people have found the Scotch Extreme Tape (bidirectional tape) at Home Depot, Lowes and Staples for $7-$10 a roll.
I have been asked about the hxt 900 servos in the Assassin. They will fly the plane but the first hit in combat and they will be no more...or at least their gear integrity might be compromised. I use the 900s on the Peregrine wings and on the Capricorn and on the Snowball but I don't use them in combat or on the Peregrine tail. For these I use the HS82MGs.
Motors. Many different motors will work, I designed the stainless steel motor mount manufactured to fit the CF2812. You can add any holes you want to fit your motors. You want a motor with 20+ oz of thrust.