Finally! Any of the Sigs will do fine. The choice is really just which size you want. Do you have space or $ constraints, or just a preference for smaller things? If so, consider the 25. If none of these are an issue, the 40 size (with a .45 engine) is the most widely recommended range to begin with. These planes are a nice size and when you begin looking for your second, third, etc plane, there are many other choices in the same size range (so you can reuse your engine). If you want to go BIG, the Senior gives you that choice. One of the guys in the club has an Electric Senior. It flies great, but the two lipo battery packs he brings to the field cost more than a couple of my planes combined! [X(] Personally, I'd go with the 25 or 40. The 25 is my preferred size, but the 40 is a more popular size and trikes are a bit easier to learn on.